prepare_release: Update hash in CHANGELOG if in a git repository
prepare_release: Update hash in CHANGELOG if in a git repository

Nikea/VisTrails,celiafish/VisTrails,hjanime/VisTrails,minesense/VisTrails,hjanime/VisTrails,hjanime/VisTrails,minesense/VisTrails,minesense/VisTrails,VisTrails/VisTrails,Nikea/VisTrails,Nikea/VisTrails,minesense/VisTrails,VisTrails/VisTrails,VisTrails/VisTrails,celiafish/VisTrails,VisTrails/VisTrails,hjanime/VisTrails,celiafish/VisTrails,celiafish/VisTrails,VisTrails/VisTrails,Nikea/VisTrails,hjanime/VisTrails,minesense/VisTrails