fix: Update nightwatch to the latest version 🚀 (#355)

Author: greenkeeper[bot]

package.json

@@ -54,7 +54,7 @@
   ],
   "peerDependencies": {
     "cucumber": "4.0.0 - 4.0.0",
-    "nightwatch": "0.9.0 - 0.9.19"
+    "nightwatch": "0.9.0 - 0.9.20"
   },
   "devDependencies": {
     "@jxnblk/simple-icons": "^1.0.0",
@@ -83,7 +83,7 @@
     "markdown-it-anchor": "^4.0.0",
     "markdown-it-table-of-contents": "^0.3.3",
     "mocha": "^5.0.0",
-    "nightwatch": "0.9.19",
+    "nightwatch": "0.9.20",
     "phantomjs-prebuilt": "^2.1.16",
     "prismjs": "^1.10.0",
     "prismjs-components-loader": "^2.0.0",