fixed base_regressor tostring
fixed base_regressor tostring

UManPychron/pychron,NMGRL/pychron,USGSDenverPychron/pychron,UManPychron/pychron,NMGRL/pychron,UManPychron/pychron,UManPychron/pychron,USGSDenverPychron/pychron,USGSDenverPychron/pychron,NMGRL/pychron,NMGRL/pychron,USGSDenverPychron/pychron