First round of Py3k updates for custodian.
Add six to requirements.
Update custodian for pmg3 compatibility.
REmove v3.1.
Update trove classifiers.
v0.7.6 release.
Better qchem handler testing. Easier to debug.
Try a solution.
Think there is a mistake in the test?
Revert "Think there is a mistake in the test?"

This reverts commit 199f6d9778d555b8bc634e069bb6419dced85207.
fixed Python 3.4 unit test error
added VaspModder class for modifying Vasp inputs
PEP8
Inc monty req.
Add a different requirements file for CI. Increment required pymatgen version.
Use different req for circle.
Merge branch 'master' into stable_py3