Merge pull request #54 from johnb30/master

Updating a few things and fixing PEP8
proposed contributors guideline
add content to contributor guidelines

This fixes a broken link, adds commit message guidelines, and references
the scikit-learn documentation.
fixes style consistency problem

the name "petrarch" should either be written as 'code' or not.
adds contributing guidelines to docs
Merge pull request #55 from zmjones/contributing

proposed contributors guideline
minor changes in a few places
Merge remote-tracking branch 'upstream/master' into minor
Remove print statements
One last time
Merge pull request #56 from johnb30/minor

Minor
making everything in synce