Removed main() from mbar.py, no longer necessary.  nose handles doctests without explicitly calling main.
Removed main() from mbar.py, no longer necessary.  nose handles doctests without explicitly calling main.

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