Tiny change to docstring
Tiny change to docstring

wesbarnett/pymbar,choderalab/pymbar,jchodera/pymbar,wesbarnett/pymbar,wesbarnett/pymbar,jchodera/pymbar,Lnaden/pymbar,kyleabeauchamp/pymbar,Lnaden/pymbar,choderalab/pymbar,Lnaden/pymbar,kyleabeauchamp/pymbar,kyleabeauchamp/pymbar,jchodera/pymbar,choderalab/pymbar,mrshirts/pymbar,kyleabeauchamp/pymbar,mrshirts/pymbar,mrshirts/pymbar,jchodera/pymbar,wesbarnett/pymbar,mrshirts/pymbar