Added sklearn to mac build script
Added sklearn to mac build script

VisTrails/VisTrails,VisTrails/VisTrails,VisTrails/VisTrails,hjanime/VisTrails,minesense/VisTrails,minesense/VisTrails,minesense/VisTrails,hjanime/VisTrails,minesense/VisTrails,hjanime/VisTrails,VisTrails/VisTrails,hjanime/VisTrails,VisTrails/VisTrails,hjanime/VisTrails,minesense/VisTrails