0.16.0 Full API and Python 3.6

• Full feature API for setting up, running, and analyzing experiments
• Supports new generalized MCMC moves, ThermodynamicStates, and other features from improved OpenMMTools
• Checkpoint feature added to reduce file size, add portability to data analysis files.
• Simulations can now alternate between phases to allow analysis even before simulations are done
• OpenEye features compartmentalized so you don't need every OpenEye feature YANK could use to use any of them
• Major under the hood speed ups to base code and MPI behavior, includes a full code refactor.
• Mol2 files can now read in multi-molecule files
• No longer uses standalone Alchemy module, uses the one built into OpenMMTools
• Added Python 3.6 support.
• Retired Python 3.4 support