Don't add aux to bibliography command

aux is automatically added to bibtex: bibtex master works
aux is not supported by biber: *only* biber master works
Cleanup
PEP8 Compliance
Merge pull request #12 from wichtounet/bib_aux_name

Bib aux name
Merge pull request #14 from wichtounet/pep8

PEP8 Compliance
Last PEP8 related change.
Merge remote-tracking branch 'upstream/develop' into git_sync

Conflicts:
	pytex/commands/versioning.py
	pytex/versioning/git.py