Fixed URL parse error when using GitHub Enterprise

[major]

GitHub Enterprise deployments are a little unpredictable and this patch removes an error when using mkdocs gh-deploy. It also includes a few PEP8 cleanups.

[d0ugal]

Thanks - what is the error that you get? I'd much rather this PR didn't wrap to 80 chars, it just hides your fix. We check for other PEP8 errors but not that one, so it doesn't help us.

[major]

@d0ugal I removed the PEP8 fixes (sorry, it's a habit!). Here's the error I get:

$ mkdocs gh-deploy                                                                                     [master]
Building documentation to directory: site
Directory site contains stale files. Use --clean to remove them.
Copying 'site' to `gh-pages` branch and pushing to GitHub.
Counting objects: 1, done.
Writing objects: 100% (1/1), 198 bytes | 0 bytes/s, done.
Total 1 (delta 0), reused 1 (delta 0)
To git@[hostname]:[username]/[repo_name].git
   5862b07..3afcc78  gh-pages -> gh-pages
Traceback (most recent call last):
  File "/usr/local/bin/mkdocs", line 9, in <module>
    load_entry_point('mkdocs==0.11.1', 'console_scripts', 'mkdocs')()
  File "/usr/local/Cellar/python/2.7.8_2/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/mkdocs-0.11.1-py2.7.egg/mkdocs/main.py", line 62, in run_main
    main(cmd, args=sys.argv[2:], options=dict(opts))
  File "/usr/local/Cellar/python/2.7.8_2/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/mkdocs-0.11.1-py2.7.egg/mkdocs/main.py", line 44, in main
    gh_deploy(config)
  File "/usr/local/Cellar/python/2.7.8_2/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/mkdocs-0.11.1-py2.7.egg/mkdocs/gh_deploy.py", line 23, in gh_deploy
    host, path = url.split('github.com:', 1)
ValueError: need more than 1 value to unpack

My company's GitHub Enterprise installation doesn't contain github.com in the URL and it causes the split to break.

[d0ugal]

PEP8 changes are a habit for me too, I'd probably enforce 80 chars, but that should all be done in one go... and I don't think Tom would agree ;)

Anyway, that is really useful thanks. Looks good to me, but will fully read shortly.

[d0ugal]

Thanks!