diff --git a/Pipfile.lock b/Pipfile.lock
index a20d058..36855b8 100644
--- a/Pipfile.lock
+++ b/Pipfile.lock
@@ -25,24 +25,24 @@
         },
         "babel": {
             "hashes": [
-                "sha256:1aac2ae2d0d8ea368fa90906567f5c08463d98ade155c0c4bfedd6a0f7160e38",
-                "sha256:d670ea0b10f8b723672d3a6abeb87b565b244da220d76b4dba1b66269ec152d4"
+                "sha256:ab49e12b91d937cd11f0b67cb259a57ab4ad2b59ac7a3b41d6c06c0ac5b0def9",
+                "sha256:bc0c176f9f6a994582230df350aa6e05ba2ebe4b3ac317eab29d9be5d2768da0"
             ],
-            "version": "==2.8.0"
+            "version": "==2.9.1"
         },
         "certifi": {
             "hashes": [
-                "sha256:017c25db2a153ce562900032d5bc68e9f191e44e9a0f762f373977de9df1fbb3",
-                "sha256:25b64c7da4cd7479594d035c08c2d809eb4aab3a26e5a990ea98cc450c320f1f"
+                "sha256:2bbf76fd432960138b3ef6dda3dde0544f27cbf8546c458e60baf371917ba9ee",
+                "sha256:50b1e4f8446b06f41be7dd6338db18e0990601dce795c2b1686458aa7e8fa7d8"
             ],
-            "version": "==2019.11.28"
+            "version": "==2021.5.30"
         },
         "chardet": {
             "hashes": [
-                "sha256:84ab92ed1c4d4f16916e05906b6b75a6c0fb5db821cc65e70cbd64a3e2a5eaae",
-                "sha256:fc323ffcaeaed0e0a02bf4d117757b98aed530d9ed4531e3e15460124c106691"
+                "sha256:0d6f53a15db4120f2b08c94f11e7d93d2c911ee118b6b30a04ec3ee8310179fa",
+                "sha256:f864054d66fd9118f2e67044ac8981a54775ec5b67aed0441892edb553d21da5"
             ],
-            "version": "==3.0.4"
+            "version": "==4.0.0"
         },
         "commonmark": {
             "hashes": [
@@ -53,17 +53,17 @@
         },
         "docutils": {
             "hashes": [
-                "sha256:0c5b78adfbf7762415433f5515cd5c9e762339e23369dbe8000d84a4bf4ab3af",
-                "sha256:c2de3a60e9e7d07be26b7f2b00ca0309c207e06c100f9cc2a94931fc75a478fc"
+                "sha256:686577d2e4c32380bb50cbb22f575ed742d58168cee37e99117a854bcd88f125",
+                "sha256:cf316c8370a737a022b72b56874f6602acf974a37a9fba42ec2876387549fc61"
             ],
-            "version": "==0.16"
+            "version": "==0.17.1"
         },
         "idna": {
             "hashes": [
-                "sha256:7588d1c14ae4c77d74036e8c22ff447b26d0fde8f007354fd48a7814db15b7cb",
-                "sha256:a068a21ceac8a4d63dbfd964670474107f541babbd2250d61922f029858365fa"
+                "sha256:b307872f855b18632ce0c21c5e45be78c0ea7ae4c15c828c20788b26921eb3f6",
+                "sha256:b97d804b1e9b523befed77c48dacec60e6dcb0b5391d57af6a65a312a90648c0"
             ],
-            "version": "==2.9"
+            "version": "==2.10"
         },
         "imagesize": {
             "hashes": [
@@ -74,10 +74,10 @@
         },
         "jinja2": {
             "hashes": [
-                "sha256:93187ffbc7808079673ef52771baa950426fd664d3aad1d0fa3e95644360e250",
-                "sha256:b0eaf100007721b5c16c1fc1eecb87409464edc10469ddc9a22a27a99123be49"
+                "sha256:1f06f2da51e7b56b8f238affdd6b4e2c61e39598a378cc49345bc1bd42a978a4",
+                "sha256:703f484b47a6af502e743c9122595cc812b0271f661722403114f71a79d0f5a4"
             ],
-            "version": "==2.11.1"
+            "version": "==3.0.1"
         },
         "markdown": {
             "hashes": [
@@ -88,69 +88,70 @@
         },
         "markupsafe": {
             "hashes": [
-                "sha256:00bc623926325b26bb9605ae9eae8a215691f33cae5df11ca5424f06f2d1f473",
-                "sha256:09027a7803a62ca78792ad89403b1b7a73a01c8cb65909cd876f7fcebd79b161",
-                "sha256:09c4b7f37d6c648cb13f9230d847adf22f8171b1ccc4d5682398e77f40309235",
-                "sha256:1027c282dad077d0bae18be6794e6b6b8c91d58ed8a8d89a89d59693b9131db5",
-                "sha256:13d3144e1e340870b25e7b10b98d779608c02016d5184cfb9927a9f10c689f42",
-                "sha256:24982cc2533820871eba85ba648cd53d8623687ff11cbb805be4ff7b4c971aff",
-                "sha256:29872e92839765e546828bb7754a68c418d927cd064fd4708fab9fe9c8bb116b",
-                "sha256:43a55c2930bbc139570ac2452adf3d70cdbb3cfe5912c71cdce1c2c6bbd9c5d1",
-                "sha256:46c99d2de99945ec5cb54f23c8cd5689f6d7177305ebff350a58ce5f8de1669e",
-                "sha256:500d4957e52ddc3351cabf489e79c91c17f6e0899158447047588650b5e69183",
-                "sha256:535f6fc4d397c1563d08b88e485c3496cf5784e927af890fb3c3aac7f933ec66",
-                "sha256:596510de112c685489095da617b5bcbbac7dd6384aeebeda4df6025d0256a81b",
-                "sha256:62fe6c95e3ec8a7fad637b7f3d372c15ec1caa01ab47926cfdf7a75b40e0eac1",
-                "sha256:6788b695d50a51edb699cb55e35487e430fa21f1ed838122d722e0ff0ac5ba15",
-                "sha256:6dd73240d2af64df90aa7c4e7481e23825ea70af4b4922f8ede5b9e35f78a3b1",
-                "sha256:717ba8fe3ae9cc0006d7c451f0bb265ee07739daf76355d06366154ee68d221e",
-                "sha256:79855e1c5b8da654cf486b830bd42c06e8780cea587384cf6545b7d9ac013a0b",
-                "sha256:7c1699dfe0cf8ff607dbdcc1e9b9af1755371f92a68f706051cc8c37d447c905",
-                "sha256:88e5fcfb52ee7b911e8bb6d6aa2fd21fbecc674eadd44118a9cc3863f938e735",
-                "sha256:8defac2f2ccd6805ebf65f5eeb132adcf2ab57aa11fdf4c0dd5169a004710e7d",
-                "sha256:98c7086708b163d425c67c7a91bad6e466bb99d797aa64f965e9d25c12111a5e",
-                "sha256:9add70b36c5666a2ed02b43b335fe19002ee5235efd4b8a89bfcf9005bebac0d",
-                "sha256:9bf40443012702a1d2070043cb6291650a0841ece432556f784f004937f0f32c",
-                "sha256:ade5e387d2ad0d7ebf59146cc00c8044acbd863725f887353a10df825fc8ae21",
-                "sha256:b00c1de48212e4cc9603895652c5c410df699856a2853135b3967591e4beebc2",
-                "sha256:b1282f8c00509d99fef04d8ba936b156d419be841854fe901d8ae224c59f0be5",
-                "sha256:b2051432115498d3562c084a49bba65d97cf251f5a331c64a12ee7e04dacc51b",
-                "sha256:ba59edeaa2fc6114428f1637ffff42da1e311e29382d81b339c1817d37ec93c6",
-                "sha256:c8716a48d94b06bb3b2524c2b77e055fb313aeb4ea620c8dd03a105574ba704f",
-                "sha256:cd5df75523866410809ca100dc9681e301e3c27567cf498077e8551b6d20e42f",
-                "sha256:cdb132fc825c38e1aeec2c8aa9338310d29d337bebbd7baa06889d09a60a1fa2",
-                "sha256:e249096428b3ae81b08327a63a485ad0878de3fb939049038579ac0ef61e17e7",
-                "sha256:e8313f01ba26fbbe36c7be1966a7b7424942f670f38e666995b88d012765b9be"
-            ],
-            "version": "==1.1.1"
+                "sha256:01a9b8ea66f1658938f65b93a85ebe8bc016e6769611be228d797c9d998dd298",
+                "sha256:023cb26ec21ece8dc3907c0e8320058b2e0cb3c55cf9564da612bc325bed5e64",
+                "sha256:0446679737af14f45767963a1a9ef7620189912317d095f2d9ffa183a4d25d2b",
+                "sha256:0717a7390a68be14b8c793ba258e075c6f4ca819f15edfc2a3a027c823718567",
+                "sha256:0955295dd5eec6cb6cc2fe1698f4c6d84af2e92de33fbcac4111913cd100a6ff",
+                "sha256:10f82115e21dc0dfec9ab5c0223652f7197feb168c940f3ef61563fc2d6beb74",
+                "sha256:1d609f577dc6e1aa17d746f8bd3c31aa4d258f4070d61b2aa5c4166c1539de35",
+                "sha256:2ef54abee730b502252bcdf31b10dacb0a416229b72c18b19e24a4509f273d26",
+                "sha256:3c112550557578c26af18a1ccc9e090bfe03832ae994343cfdacd287db6a6ae7",
+                "sha256:47ab1e7b91c098ab893b828deafa1203de86d0bc6ab587b160f78fe6c4011f75",
+                "sha256:49e3ceeabbfb9d66c3aef5af3a60cc43b85c33df25ce03d0031a608b0a8b2e3f",
+                "sha256:4efca8f86c54b22348a5467704e3fec767b2db12fc39c6d963168ab1d3fc9135",
+                "sha256:53edb4da6925ad13c07b6d26c2a852bd81e364f95301c66e930ab2aef5b5ddd8",
+                "sha256:594c67807fb16238b30c44bdf74f36c02cdf22d1c8cda91ef8a0ed8dabf5620a",
+                "sha256:611d1ad9a4288cf3e3c16014564df047fe08410e628f89805e475368bd304914",
+                "sha256:6557b31b5e2c9ddf0de32a691f2312a32f77cd7681d8af66c2692efdbef84c18",
+                "sha256:693ce3f9e70a6cf7d2fb9e6c9d8b204b6b39897a2c4a1aa65728d5ac97dcc1d8",
+                "sha256:6a7fae0dd14cf60ad5ff42baa2e95727c3d81ded453457771d02b7d2b3f9c0c2",
+                "sha256:6c4ca60fa24e85fe25b912b01e62cb969d69a23a5d5867682dd3e80b5b02581d",
+                "sha256:7d91275b0245b1da4d4cfa07e0faedd5b0812efc15b702576d103293e252af1b",
+                "sha256:905fec760bd2fa1388bb5b489ee8ee5f7291d692638ea5f67982d968366bef9f",
+                "sha256:97383d78eb34da7e1fa37dd273c20ad4320929af65d156e35a5e2d89566d9dfb",
+                "sha256:984d76483eb32f1bcb536dc27e4ad56bba4baa70be32fa87152832cdd9db0833",
+                "sha256:a30e67a65b53ea0a5e62fe23682cfe22712e01f453b95233b25502f7c61cb415",
+                "sha256:ab3ef638ace319fa26553db0624c4699e31a28bb2a835c5faca8f8acf6a5a902",
+                "sha256:b2f4bf27480f5e5e8ce285a8c8fd176c0b03e93dcc6646477d4630e83440c6a9",
+                "sha256:b7f2d075102dc8c794cbde1947378051c4e5180d52d276987b8d28a3bd58c17d",
+                "sha256:be98f628055368795d818ebf93da628541e10b75b41c559fdf36d104c5787066",
+                "sha256:d7f9850398e85aba693bb640262d3611788b1f29a79f0c93c565694658f4071f",
+                "sha256:f5653a225f31e113b152e56f154ccbe59eeb1c7487b39b9d9f9cdb58e6c79dc5",
+                "sha256:f826e31d18b516f653fe296d967d700fddad5901ae07c622bb3705955e1faa94",
+                "sha256:f8ba0e8349a38d3001fae7eadded3f6606f0da5d748ee53cc1dab1d6527b9509",
+                "sha256:f9081981fe268bd86831e5c75f7de206ef275defcb82bc70740ae6dc507aee51",
+                "sha256:fa130dd50c57d53368c9d59395cb5526eda596d3ffe36666cd81a44d56e48872"
+            ],
+            "version": "==2.0.1"
         },
         "packaging": {
             "hashes": [
-                "sha256:3c292b474fda1671ec57d46d739d072bfd495a4f51ad01a055121d81e952b7a3",
-                "sha256:82f77b9bee21c1bafbf35a84905d604d5d1223801d639cf3ed140bd651c08752"
+                "sha256:5b327ac1320dc863dca72f4514ecc086f31186744b84a230374cc1fd776feae5",
+                "sha256:67714da7f7bc052e064859c05c595155bd1ee9f69f76557e21f051443c20947a"
             ],
-            "version": "==20.3"
+            "version": "==20.9"
         },
         "pygments": {
             "hashes": [
-                "sha256:647344a061c249a3b74e230c739f434d7ea4d8b1d5f3721bc0f3558049b38f44",
-                "sha256:ff7a40b4860b727ab48fad6360eb351cc1b33cbf9b15a0f689ca5353e9463324"
+                "sha256:a18f47b506a429f6f4b9df81bb02beab9ca21d0a5fee38ed15aef65f0545519f",
+                "sha256:d66e804411278594d764fc69ec36ec13d9ae9147193a1740cd34d272ca383b8e"
             ],
-            "version": "==2.6.1"
+            "version": "==2.9.0"
         },
         "pyparsing": {
             "hashes": [
-                "sha256:4c830582a84fb022400b85429791bc551f1f4871c33f23e44f353119e92f969f",
-                "sha256:c342dccb5250c08d45fd6f8b4a559613ca603b57498511740e65cd11a2e7dcec"
+                "sha256:c203ec8783bf771a155b207279b9bccb8dea02d8f0c9e5f8ead507bc3246ecc1",
+                "sha256:ef9d7589ef3c200abe66653d3f1ab1033c3c419ae9b9bdb1240a85b024efc88b"
             ],
-            "version": "==2.4.6"
+            "version": "==2.4.7"
         },
         "pytz": {
             "hashes": [
-                "sha256:1c557d7d0e871de1f5ccd5833f60fb2550652da6be2693c1e02300743d21500d",
-                "sha256:b02c06db6cf09c12dd25137e563b31700d3b80fcc4ad23abb7a315f2789819be"
+                "sha256:83a4a90894bf38e243cf052c8b58f381bfe9a7a483f6a9cab140bc7f702ac4da",
+                "sha256:eb10ce3e7736052ed3623d49975ce333bcd712c7bb19a58b9e2089d4057d0798"
             ],
-            "version": "==2019.3"
+            "version": "==2021.1"
         },
         "recommonmark": {
             "hashes": [
@@ -162,24 +163,17 @@
         },
         "requests": {
             "hashes": [
-                "sha256:43999036bfa82904b6af1d99e4882b560e5e2c68e5c4b0aa03b655f3d7d73fee",
-                "sha256:b3f43d496c6daba4493e7c431722aeb7dbc6288f52a6e04e7b6023b0247817e6"
-            ],
-            "version": "==2.23.0"
-        },
-        "six": {
-            "hashes": [
-                "sha256:236bdbdce46e6e6a3d61a337c0f8b763ca1e8717c03b369e87a7ec7ce1319c0a",
-                "sha256:8f3cd2e254d8f793e7f3d6d9df77b92252b52637291d0f0da013c76ea2724b6c"
+                "sha256:27973dd4a904a4f13b263a19c866c13b92a39ed1c964655f025f3f8d3d75b804",
+                "sha256:c210084e36a42ae6b9219e00e48287def368a26d03a048ddad7bfee44f75871e"
             ],
-            "version": "==1.14.0"
+            "version": "==2.25.1"
         },
         "snowballstemmer": {
             "hashes": [
-                "sha256:209f257d7533fdb3cb73bdbd24f436239ca3b2fa67d56f6ff88e86be08cc5ef0",
-                "sha256:df3bac3df4c2c01363f3dd2cfa78cce2840a79b9f1c2d2de9ce8d31683992f52"
+                "sha256:b51b447bea85f9968c13b650126a888aabd4cb4463fca868ec596826325dedc2",
+                "sha256:e997baa4f2e9139951b6f4c631bad912dfd3c792467e2f03d7239464af90e914"
             ],
-            "version": "==2.0.0"
+            "version": "==2.1.0"
         },
         "sphinx": {
             "hashes": [
@@ -221,10 +215,10 @@
         },
         "sphinxcontrib-htmlhelp": {
             "hashes": [
-                "sha256:3c0bc24a2c41e340ac37c85ced6dafc879ab485c095b1d65d2461ac2f7cca86f",
-                "sha256:e8f5bb7e31b2dbb25b9cc435c8ab7a79787ebf7f906155729338f3156d93659b"
+                "sha256:d412243dfb797ae3ec2b59eca0e52dac12e75a241bf0e4eb861e450d06c6ed07",
+                "sha256:f5f8bb2d0d629f398bf47d0d69c07bc13b65f75a81ad9e2f71a63d4b7a2f6db2"
             ],
-            "version": "==1.0.3"
+            "version": "==2.0.0"
         },
         "sphinxcontrib-jsmath": {
             "hashes": [
@@ -242,17 +236,18 @@
         },
         "sphinxcontrib-serializinghtml": {
             "hashes": [
-                "sha256:eaa0eccc86e982a9b939b2b82d12cc5d013385ba5eadcc7e4fed23f4405f77bc",
-                "sha256:f242a81d423f59617a8e5cf16f5d4d74e28ee9a66f9e5b637a18082991db5a9a"
+                "sha256:352a9a00ae864471d3a7ead8d7d79f5fc0b57e8b3f95e9867eb9eb28999b92fd",
+                "sha256:aa5f6de5dfdf809ef505c4895e51ef5c9eac17d0f287933eb49ec495280b6952"
             ],
-            "version": "==1.1.4"
+            "version": "==1.1.5"
         },
         "urllib3": {
             "hashes": [
-                "sha256:2f3db8b19923a873b3e5256dc9c2dedfa883e33d87c690d9c7913e1f40673cdc",
-                "sha256:87716c2d2a7121198ebcb7ce7cccf6ce5e9ba539041cfbaeecfb641dc0bf6acc"
+                "sha256:753a0374df26658f99d826cfe40394a686d05985786d946fbe4165b5148f5a7c",
+                "sha256:a7acd0977125325f516bda9735fa7142b909a8d01e8b2e4c8108d0984e6e0098"
             ],
-            "version": "==1.25.8"
+            "index": "pypi",
+            "version": "==1.26.5"
         }
     },
     "develop": {}
diff --git a/requirements.txt b/requirements.txt
index 2ffcfb7..b705f7d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,30 +1,29 @@
--i https://pypi.org/simple
+-i https://pypi.org/simple/
 alabaster==0.7.12
-babel==2.8.0
-certifi==2019.11.28
-chardet==3.0.4
+babel==2.9.1
+certifi==2021.5.30
+chardet==4.0.0
 commonmark==0.9.1
-docutils==0.16
-idna==2.9
+docutils==0.17.1
+idna==2.10
 imagesize==1.2.0
-jinja2==2.11.1
+jinja2==3.0.1
 markdown==3.0.1
-markupsafe==1.1.1
-packaging==20.3
-pygments==2.6.1
-pyparsing==2.4.6
-pytz==2019.3
+markupsafe==2.0.1
+packaging==20.9
+pygments==2.9.0
+pyparsing==2.4.7
+pytz==2021.1
 recommonmark==0.6.0
-requests==2.23.0
-six==1.14.0
-snowballstemmer==2.0.0
+requests==2.25.1
+snowballstemmer==2.1.0
 sphinx-markdown-tables==0.0.12
 sphinx-rtd-theme==0.4.3
 sphinx==2.4.4
 sphinxcontrib-applehelp==1.0.2
 sphinxcontrib-devhelp==1.0.2
-sphinxcontrib-htmlhelp==1.0.3
+sphinxcontrib-htmlhelp==2.0.0
 sphinxcontrib-jsmath==1.0.1
 sphinxcontrib-qthelp==1.0.3
-sphinxcontrib-serializinghtml==1.1.4
-urllib3==1.25.8
+sphinxcontrib-serializinghtml==1.1.5
+urllib3==1.26.5