Fix mypy check

[Lee-W]

• style
  • fix all the mypy warning
  • config: move .flake8 to setup.cfg and add mypy, pytest config
• ci
  • add mypy check
  • add stricter config but comment out those we not yet follow
  • remove redundant arugment (it's been configed in setup.cfg)
• test(cz/customize): add test case initialize_cz_customize_failed

[codecov]

Codecov Report

Merging #156 into master will increase coverage by 0.03%.
The diff coverage is 93.10%.

@@            Coverage Diff             @@
##           master     #156      +/-   ##
==========================================
+ Coverage   91.54%   91.58%   +0.03%     
==========================================
  Files          33       33              
  Lines         769      784      +15     
==========================================
+ Hits          704      718      +14     
- Misses         65       66       +1     

Flag	Coverage Δ
#unittests	91.58% <93.10%> (+0.03%)	⬆️

Impacted Files	Coverage Δ
commitizen/config/__init__.py	82.60% <50.00%> (ø)
commitizen/cz/customize/customize.py	84.78% <78.57%> (-0.22%)	⬇️
commitizen/commands/check.py	100.00% <100.00%> (ø)
commitizen/config/base_config.py	91.30% <100.00%> (ø)
commitizen/config/ini_config.py	84.61% <100.00%> (+0.83%)	⬆️
commitizen/config/toml_config.py	93.10% <100.00%> (+0.51%)	⬆️
commitizen/cz/__init__.py	100.00% <100.00%> (ø)
commitizen/cz/base.py	100.00% <100.00%> (ø)
...en/cz/conventional_commits/conventional_commits.py	100.00% <100.00%> (ø)
commitizen/cz/jira/jira.py	100.00% <100.00%> (ø)
... and 6 more

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[Lee-W]

@woile I made some change on config files (i.e. setup.cfg) of this project. Could you check whether they make sense to you? Other than that is just fixing mypy warnings.

[woile]

Thanks for taking the time to do this!

[Lee-W]

@woile If other configurations look good to you, I'll merge this pull request late today 🙂

[woile]

Yes it's fine 👍 if any of the new settings starts annoying we can discuss about changing it.