Verify Improve Fixes

[JayDwee]

Summary

close #421 close #418 close #416

Checklist

• [x] This PR fixes an issue.
• [x] This PR adds something new (e.g. new method or parameters).
• [ ] This PR is a breaking change (e.g. methods or parameters removed/renamed)
• [ ] This PR is not a code change (e.g. documentation, README, ...)

• [x] Have you tested the changes? (pytest & dpytest)
• [x] Have you followed PEP-8 for naming and styling?
• [x] Has your code been properly documented with RestructuredText docstrings?
• [x] Have you added your changes to CHANGELOG.md under the [Unreleased] heading?
• [x] If your code added new bot commands, have you updated documentation.json?

• [x] All of this code is your own, or follows the author repo's licence.

[codecov[bot]]

Codecov Report

Merging #422 (9b3a469) into master (4261acc) will increase coverage by 0.02%. The diff coverage is 90.90%.

@@            Coverage Diff             @@
##           master     #422      +/-   ##
==========================================
+ Coverage   87.33%   87.35%   +0.02%     
==========================================
  Files         124      125       +1     
  Lines        9046     9110      +64     
==========================================
+ Hits         7900     7958      +58     
- Misses       1146     1152       +6     

Flag	Coverage Δ
unittests	87.35% <90.90%> (+0.02%)	:arrow_up:

Flags with carried forward coverage won't be shown. Click here to find out more.

Files Changed	Coverage Δ
koala/cogs/verification/cog.py	85.45% <44.44%> (-3.66%)	:arrow_down:
koala/cogs/verification/core.py	81.92% <94.73%> (+0.85%)	:arrow_up:
tests/cogs/verification/test_core.py	100.00% <100.00%> (ø)