Remove pymbar_datasets.py because it contains untested, unused, broken code
Remove pymbar_datasets.py because it contains untested, unused, broken code

mrshirts/pymbar,choderalab/pymbar,choderalab/pymbar,mrshirts/pymbar,Lnaden/pymbar,Lnaden/pymbar,choderalab/pymbar,mrshirts/pymbar,Lnaden/pymbar,mrshirts/pymbar