Raise error when there are staged changes.
Raise error when there are staged changes.

edisongustavo/asv,qwhelan/asv,pv/asv,pv/asv,mdboom/asv,spacetelescope/asv,qwhelan/asv,giltis/asv,pv/asv,ericdill/asv,giltis/asv,qwhelan/asv,airspeed-velocity/asv,giltis/asv,qwhelan/asv,waylonflinn/asv,edisongustavo/asv,spacetelescope/asv,edisongustavo/asv,ericdill/asv,spacetelescope/asv,airspeed-velocity/asv,mdboom/asv,waylonflinn/asv,airspeed-velocity/asv,waylonflinn/asv,ericdill/asv,pv/asv,ericdill/asv,airspeed-velocity/asv,mdboom/asv,mdboom/asv,spacetelescope/asv