Coverage plugin requires cov-core>=1.12. Install it.
Our style is PEP8
Make test also work on Windows that uses backslash as path delimiter
Make requirements for tox and CI match those in setup.py (not related to fixing failing CI, just fix it while we're here and remember about it).
unittest discover is not available in Python 2.6. Revert to 7f29234754be0f7d9a248ac0ef045d9306858eac.
Updated comment
Added development requirements.
Updated six version.
Fixed missing return that broke test discovery.
Also fixed test that would fail on some setups
Fix pkg1 test failures.

Renamed egg test package from pkg1 to pkgegg as the sys.path shenanigans
were making other tests fail.
Fixed eggdiscovery documentation warning
Added eggdiscovery import in test module to prevent Travis failures
Absolute import of discovery module to fix Travis failures
Fixed py3 build