PR: Change from pep8 to pycodestyle for style analysis

[rlaverde]

Fixes #3197

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I change only the necessary in the code, I didn't change variables, classes, or config options names.

When checking dependencies, is required 0.6 version of pycodestyle, this is a bit outdated, should we updated it?
PEP8_REQVER = '>=0.6'

[ccordoba12]

When checking dependencies, is required 0.6 version of pycodestyle, this is a bit outdated, should we updated it?

Sure, please update it to a more recent version.

[rlaverde]

Sure, please update it to a more recent version.

Done 😄

[ccordoba12]

Could you add a test to verify that CodeEditor is showing pep8 warnings? That's something that's not tested at the moment, and given the importance of this change, I think we should start doing it :-)

[ccordoba12]

test_codeanalysis is now failing @rlaverde, please review that.

[rlaverde]

The new version of pycodestyle now detects one more style error than the previous version, I updated the num_results

spyder/utils/tests/data/example.py:53:1: E305 expected 2 blank lines after class or function definition, found 1

[ccordoba12]

Thanks @rlaverde!

[ccordoba12]

Thanks @rlaverde!

One missing thing: Please update our Readme too.