Disable warnings related to the use of assert in the tests directory as reported with lint-vetting (#792)

Disable warnings related to the use of assert in the tests directory as reported with `lint-vetting`

This adds a few additional files to the per-file-ignore list within the flake8 configuration with an exemption for S101 which is reported by flake8-bandit as part of the wemake style guide which is being vetted.
The list was also alphabetized to ensure new entries were placed in a sane location.
A note was added to the top of the flake8 per-file-ignores indicating that the glob for the tests folder ignoring s101 can be added later. Currently there is a conflict between globs and per-file entries.  See PyCQA/flake8#670
This eliminates the S101 entry from the output of tox -e lint-vetting so users of it can see messages only related to the changes they are making and not for files that were previously added to the repository:
1     C812 missing trailing comma
1     RST304 Unknown interpreted text role "mod".
- 13    S101 Use of assert detected. The enclosed code will be removed when compiling to optimised byte code.
1     S404 Consider possible security implications associated with the subprocess module.
1     S603 subprocess call - check for execution of untrusted input.
2     S604 Function call with shell=True parameter identified, possible security issue.
2     WPS111 Found too short name: p < 2
2     WPS115 Found upper-case constant in a class: KEGEX
3     WPS201 Found module with too many imports: 13 > 12
6     WPS210 Found too many local variables: 6 > 5
3     WPS220 Found too deep nesting: 24 > 20
2     WPS221 Found line with high Jones Complexity: 16 > 14
3     WPS226 Found string literal over-use: test_option > 3
9     WPS305 Found `f` string
1     WPS316 Found context manager with too many assignments
6     WPS317 Found incorrect multi-line parameters
2     WPS323 Found `%` string formatting
4     WPS324 Found inconsistent `return` statement
2     WPS414 Found incorrect unpacking target
1     WPS430 Found nested function: getcwd
14    WPS436 Found protected module import: _curses
3     WPS450 Found protected object import: _CursesWindow
1     WPS602 Found using `@staticmethod`
Related #713

Reviewed-by: Sviatoslav Sydorenko <webknjaz+github/[email protected]>
Reviewed-by: Bradley A. Thornton <[email protected]>
Reviewed-by: None <None>

Author: cidrblock

.flake8

@@ -59,8 +59,18 @@ inline-quotes = "
 max-line-length = 100
 
 # Allow certain violations in certain files:
-# Please keep this list sorted, as it will be easier for others to find and add entries in the future
+# Please keep both sections of this list sorted, as it will be easier for others to find and add entries in the future
 per-file-ignores =
+  # The following ignores have been researched and should be considered permanent
+  # each should be preceeded with an explanation of each of the error codes
+  # If other ignores are added for a specific file in the section following this,
+  # these will need to be added to that line as well.
+
+  # S101: Allow the use of assert within the tests directory, since tests require it.
+  tests/**.py: S101
+
+  # The following were present during the initial implementation.
+  # They are expected to be fixed and unignored over time.
   docs/_ext/single_sourced_data.py: D400, D403, DAR101, DAR201, N817, P103, WPS110, WPS111, WPS201, WPS202, WPS210, WPS213, WPS221, WPS229, WPS231, WPS237, WPS305, WPS318, WPS323, WPS331, WPS336, WPS347, WPS407, WPS432, WPS440, WPS441, WPS453, WPS504
   docs/_ext/spelling_stub_ext.py: DAR101, DAR201
   docs/conf.py: WPS221, WPS226, WPS301, WPS305, WPS323, WPS420, WPS429, WPS433