Add automatic PEP8 checking to Travis

[tmylk]

A good example of this is sklearn

[souravsingh]

@tmylk I am interested in working on the issue.

[tmylk]

Great. Let's add pep8, (not autopep8) to travis.yml. We don't care about long lines so it should be ignored. See this for an example https://gist.github.com/MichaelCurrie/802ce28c993ff2dd632c

[markroxor]

@tmylk we can use pep8 but this will scan the complete repo and while working with the forks I have realised that there are way too many formatting issues. So the Travis build will fail until we rectify them all. So along with pep8 integration do you want that all the errors raised by pep8 should also be fixed under this PR?

[tmylk]

@markroxor Yes, an initial autopep8 is definitely a part of this PR.

[souravsingh]

I will be making a PR for autopep8 shortly

[tmylk]

Ping @souravsingh . Thanks for taking this up!

[souravsingh]

Apologies for not responding to the issue. I had to some commitments which came up suddenly and had to travel. I will finish up the issue once I get back( which should be by 28th)

[nishnik]

I think this issue is solved, isn't it ?

[tmylk]

@nishnik It was moved to #973 by @souravsingh
your help in incorporating the coala suggestions into the code would be very welcome