Change some variable names and add comment.
Record that .normalize() output now returns lowercase, to avoid
duplicate specs as output.
Remove way too detailed test (does not match current program's output anymore).
Fix a few broken tests.
Fix some broken tests for Python 3.
Work around missing cmp() function in Python 3.
Cast maps to explicit lists.
PEP8ify.
Fix apparent order of preds in str()'ed normalized specs.
Add "six" dependency to tox envs.
Deprecate assertItemsEqual in favor of assertCountEqual.
Merge remote-tracking branch 'origin/future' into local

Conflicts:
	piptools/package_manager.py