Some cleanup to travis, build py33
Some cleanup to travis, build py33

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