Add pep8 config, use pep8 in travis

also, fix E111-E113 errors:
E111 - indentation is not a multiple of four
E112 - expected an indented block
E113 - unexpected indentation

On Sat, Dec 27, 2014 at 02:13:31PM -0800, Joachim Durchholz wrote:
>  > +# E113 - unexpected indentation
> 
>    "Unexpected indentation" can happen for an indented comment, which is not
>    a syntax error.

In that case - no error or warning will be raised.