Make running pycodestyle slightly more ergonomic.

[zenhack]

The same change was made to the pylint script a while back.

[coveralls]

Pull Request Test Coverage Report for Build 1909

• 0 of 0 (NaN%) changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 55.168%

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Totals
Change from base Build 1908:	0.0%
Covered Lines:	2119
Relevant Lines:	3841

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💛 - Coveralls

[ianballou]

@zenhack I can merge this as soon as it gets a rebase

[zenhack]

Done.