mBuild 0.7.1

Merge pull request #352 from summeraz/use_parmed

Use Parmed loaders by default, remove Mdtraj dependency

mBuild 0.7.0

Bump version to 0.7.0

mBuild 0.6.1

Tag 0.6.1

mBuild 0.6.0

Tag 0.6.0

0.5.2

Merge pull request #131 from ctk3b/dev-package

Fix requirements.