Repository: sdv-dev/CTGAN (language: python)

Issue:
Increase code style lint
### Problem Description

Currently our code is being validated only by `flake8` 'vanilla' and just a few plugins. We would like to increase the code style checks by adding more add-on's that follow our code style and our standards.

Also we would like to ensure that our docstrings are properly written and follow the rest of our format.

### Additional context

We have performed this task already on [RDT](https://github.com/sdv-dev/RDT/) , more precisely on the following issue:
https://github.com/sdv-dev/RDT/issues/248#issuecomment-932085083

### Docstring plugin

We need to add `pydocstyle` plugin with the following lines on our `setup.cfg` file as we are following the [google convention](https://google.github.io/styleguide/pyguide.html#38-comments-and-docstrings).

```
[pydocstyle]
convention = google
add-ignore = D107, D407, D417
```

### Flake8 plugins to be added
Flake8 comes with a lot of different addons that we can use to adapt it to our codestyle and checking, here is a list of plugins that I found to be interesting for us:

* `flake8-builtins` - Check for python builtins being used as variables or parameters.
* `flake8-comprehensions` - Helps you write better list/set/dict comprehensions.
* `flake8-debugger` - Debug statement checker.
* `flake8-variables-names` - Extension that helps to make more readable variables names.
* `Dlint` - Tool for encouraging best coding practices and helping ensure Python code is secure.
* `flake8-mock` - Provides checking mock non-existent methods.
* `flake8-fixme` - Check for FIXME, TODO and other temporary developer notes.
* `flake8-eradicate` - Plugin to find commented out or dead code.
* `flake8-mutable` - Extension for mutable default arguments.
* `flake8-print` - Check for print statements in python files.
* `flake8-pytest-style` - Plugin checking common style issues or inconsistencies.
* `flake8-quotes` - Extension for checking quotes in python.
* `flake8-multiline-containers` - Plugin to ensure a consistent format for multiline containers.
* `pandas-vet` - Plugin that provides opinionated linting for pandas code.
* `pep8-naming` - Check the PEP-8 naming conventions.
* `flake8-expression-complexity` - Plugin to validate expressions complexity.
*  `flake8-sfs` - String formatting.



Discussion / hints:

Fix patch:
diff --git a/setup.py b/setup.py
index c7b05a0b..6ed63185 100644
--- a/setup.py
+++ b/setup.py
@@ -51,6 +51,7 @@
     'flake8-mock>=0.3,<0.4',
     'flake8-mutable>=1.2.0,<1.3',
     'flake8-absolute-import>=1.0,<2',
+    'flake8-fixme>=1.1.1,<1.2',
     'flake8-expression-complexity>=0.0.9,<0.1',
     'flake8-eradicate>=1.1.0,<1.2',
     'dlint>=0.11.0,<0.12',


Test patch:
diff --git a/tests/unit/synthesizer/test_ctgan.py b/tests/unit/synthesizer/test_ctgan.py
index 52cf1dab..56894a0a 100644
--- a/tests/unit/synthesizer/test_ctgan.py
+++ b/tests/unit/synthesizer/test_ctgan.py
@@ -284,7 +284,6 @@ def test__validate_discrete_columns(self):
 
         Note:
             - could create another function for numpy array
-            - TODO: it is currently a integration test, needs to be changed to a proper unit test
         """
         data = pd.DataFrame({
             'discrete': ['a', 'b']