start enforcing linting on tests directory

[a-dubs]

This would require fixing a bunch of test files
after running tox -e format with changes provided below:

tests/__init__.py:1:1: D104 Missing docstring in public package
tests/conftest.py:1:1: D100 Missing docstring in public module
tests/integration_tests/__init__.py:1:1: D104 Missing docstring in public package
tests/integration_tests/gce/__init__.py:1:1: D104 Missing docstring in public package
tests/integration_tests/gce/test_launch.py:1:1: D100 Missing docstring in public module
tests/integration_tests/gce/test_launch.py:10:5: D103 Missing docstring in public function
tests/integration_tests/ibm/__init__.py:1:1: D104 Missing docstring in public package
tests/integration_tests/ibm/test_launch.py:1:1: D100 Missing docstring in public module
tests/integration_tests/ibm/test_launch.py:11:5: D103 Missing docstring in public function
tests/integration_tests/test_public_api.py:1:1: D100 Missing docstring in public module
tests/integration_tests/test_public_api.py:21:5: D103 Missing docstring in public function
tests/integration_tests/test_public_api.py:38:5: D103 Missing docstring in public function
tests/integration_tests/test_public_api.py:43:5: D103 Missing docstring in public function
tests/integration_tests/test_public_api.py:56:5: D103 Missing docstring in public function
tests/integration_tests/test_public_api.py:150:5: D103 Missing docstring in public function
tests/unit_tests/azure/test_cloud.py:137:7: D101 Missing docstring in public class
tests/unit_tests/azure/test_cloud.py:138:9: D102 Missing docstring in public method
tests/unit_tests/azure/test_cloud.py:175:9: D102 Missing docstring in public method
tests/unit_tests/azure/test_cloud.py:242:9: D102 Missing docstring in public method
tests/unit_tests/azure/test_cloud.py:283:9: D102 Missing docstring in public method
tests/unit_tests/azure/test_cloud.py:335:9: D102 Missing docstring in public method
tests/unit_tests/azure/test_cloud.py:393:9: D102 Missing docstring in public method
tests/unit_tests/ec2/__init__.py:1:1: D104 Missing docstring in public package
tests/unit_tests/ec2/test_cloud.py:116:9: D205 1 blank line required between summary line and description
tests/unit_tests/ec2/test_cloud.py:116:9: D400 First line should end with a period
tests/unit_tests/ec2/test_cloud.py:125:9: D200 One-line docstring should fit on one line
tests/unit_tests/ec2/test_cloud.py:125:9: D400 First line should end with a period
tests/unit_tests/ec2/test_cloud.py:134:9: D200 One-line docstring should fit on one line
tests/unit_tests/ec2/test_cloud.py:134:9: D400 First line should end with a period
tests/unit_tests/gce/test_cloud.py:19:9: D107 Missing docstring in `__init__`
tests/unit_tests/gce/test_cloud.py:25:5: D400 First line should end with a period
tests/unit_tests/gce/test_cloud.py:40:5: D400 First line should end with a period
tests/unit_tests/gce/test_cloud.py:69:9: D200 One-line docstring should fit on one line
tests/unit_tests/gce/test_cloud.py:89:9: D102 Missing docstring in public method
tests/unit_tests/gce/test_cloud.py:308:9: D102 Missing docstring in public method
tests/unit_tests/ibm/test_cloud.py:38:5: D103 Missing docstring in public function
tests/unit_tests/ibm/test_instance.py:18:7: D101 Missing docstring in public class
tests/unit_tests/ibm/test_instance.py:45:9: D200 One-line docstring should fit on one line
tests/unit_tests/ibm_classic/test_cloud.py:1:1: D100 Missing docstring in public module
tests/unit_tests/ibm_classic/test_cloud.py:29:5: D103 Missing docstring in public function
tests/unit_tests/ibm_classic/test_cloud.py:44:5: D103 Missing docstring in public function
tests/unit_tests/ibm_classic/test_cloud.py:58:5: D103 Missing docstring in public function
tests/unit_tests/ibm_classic/test_cloud.py:65:5: D103 Missing docstring in public function
tests/unit_tests/ibm_classic/test_cloud.py:72:5: D103 Missing docstring in public function
tests/unit_tests/ibm_classic/test_cloud.py:83:5: D103 Missing docstring in public function
tests/unit_tests/ibm_classic/test_cloud.py:120:5: D103 Missing docstring in public function
tests/unit_tests/lxd/test_cloud.py:142:7: D101 Missing docstring in public class
tests/unit_tests/lxd/test_cloud.py:201:7: D101 Missing docstring in public class
tests/unit_tests/oci/test_instance.py:231:9: D401 First line of docstring should be in imperative mood: "Mocks VNIC attachments and VNIC data based on custom VNIC configurations."
tests/unit_tests/qemu/test_qemu_instance.py:1:1: D100 Missing docstring in public module
tests/unit_tests/qemu/test_qemu_instance.py:7:5: D103 Missing docstring in public function
tests/unit_tests/qemu/test_qemu_instance.py:17:5: D103 Missing docstring in public function
tests/unit_tests/qemu/test_qemu_instance.py:25:5: D103 Missing docstring in public function
tests/unit_tests/qemu/test_qemu_instance.py:37:5: D103 Missing docstring in public function
tests/unit_tests/qemu/test_qemu_instance.py:49:5: D103 Missing docstring in public function
tests/unit_tests/test_cloud.py:160:9: D102 Missing docstring in public method
Found 56 errors.

It would look something like this:

diff --git a/tox.ini b/tox.ini
index f79031d..8df7e49 100644
--- a/tox.ini
+++ b/tox.ini
@@ -26,29 +26,29 @@ commands = {envpython} -m pytest --doctest-modules {posargs:--cov pycloudlib}
 envdir = {[common]envdir}
 deps =
     {[common]deps}
-commands = {envpython} -m mypy pycloudlib examples setup.py
+commands = {envpython} -m mypy pycloudlib tests examples setup.py
 
 [testenv:ruff]
 envdir = {[common]envdir}
 deps = {[common]deps}
-commands = {envpython} -m ruff check -- pycloudlib examples setup.py
+commands = {envpython} -m ruff check -- pycloudlib tests examples setup.py
 
 [testenv:pylint]
 envdir = {[common]envdir}
 deps = {[common]deps}
-commands = {envpython} -m pylint --max-line-length=100 pycloudlib examples setup.py
+commands = {envpython} -m pylint --max-line-length=100 pycloudlib tests examples setup.py
 
 [testenv:format-check]
 envdir = {[common]envdir}
 deps = {[common]deps}
-commands = {envpython} -m ruff format --check -- .
+commands = {envpython} -m ruff format --check -- pycloudlib tests examples setup.py
 
 [testenv:format]
 envdir = {[common]envdir}
 deps = {[common]deps}
 commands =
-    {envpython} -m ruff format -- .
-    {envpython} -m ruff check --fix -- pycloudlib examples setup.py
+    {envpython} -m ruff format -- pycloudlib tests examples setup.py
+    {envpython} -m ruff check --fix -- pycloudlib tests examples setup.py
 
 [testenv:docs]
 # Docs uses a separate environment because the changedir will
@@ -70,12 +70,12 @@ deps =
 [testenv:tip-pylint]
 envdir = {[tip]envdir}
 deps = {[tip]deps}
-commands = {envpython} -m pylint --max-line-length=100 pycloudlib examples setup.py
+commands = {envpython} -m pylint --max-line-length=100 pycloudlib tests examples setup.py
 
 [testenv:tip-ruff]
 envdir = {[tip]envdir}
 deps = {[tip]deps}
-commands = {envpython} -m ruff check -- pycloudlib examples setup.py
+commands = {envpython} -m ruff check -- pycloudlib tests examples setup.py
 
 [testenv:integration-tests]
 commands = {envpython} -m pytest --log-cli-level=INFO -svv {posargs:tests/integration_tests}