Add pre-commit support and fix pre-commit check error

[linw1995]

• 593d622 Fix pre-commit check error
• 68ebbc1 Add pre-commit
• 3c4843e Replace pytest.ini with setup.cfg
• a339f57 Remove MANIFEST.in
• 0b67a27 Fix .travis.yml error
• fcec757 Fix .travis.yml error
  .travis.yml currently not support merging multi maps
• 3bf1197 Fix setup.cfg error
  Don't move pytest settings into setup.cfg
  Cannot setup log_format in setup.cfg, because of InterpolationMissingOptionError` pytest-dev/pytest#3062

[codecov]

Codecov Report

Merging #32 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff          @@
##           master    #32   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files           7      7           
  Lines         221    220    -1     
  Branches       31     31           
=====================================
- Hits          221    220    -1

Impacted Files	Coverage Δ
data_extractor/item.py	100% <ø> (ø)	⬆️
data_extractor/lxml.py	100% <ø> (ø)	⬆️
data_extractor/exceptions.py	100% <ø> (ø)	⬆️
data_extractor/abc.py	100% <100%> (ø)	⬆️

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