Merge pull request choderalab#94 from jchodera/master

Added system.pdb file for DHFR

Merge pull request choderalab#81 from jchodera/logging

Added printing of number of atoms to test-openmm-platforms

Merge pull request choderalab#80 from jchodera/fix-parmed-dependency

Fixed parmed dependency for new parmed 2.0 release.

Removed Python 2.7 from appveyor build because win-32 openmm only sup…

…ports Python 3.3 and 3.4.

Merge pull request choderalab#33 from jchodera/segfault-workaround

[WIP] Segfault workaround

Merge pull request choderalab#30 from kyleabeauchamp/py3

Fixes to init.py

Merge pull request choderalab#28 from jchodera/add-sobol

Added Sobol subrandom sampling approach to initialize particle positions