Add rcov task as a dependency on heckle being run
Add rcov task as a dependency on heckle being run

* There is no point in running heckle if the rcov task fails, since it means
  that coverage has dropped.

artemeff/virtus,XescuGC/virtus,faucct/virtus,dslh/virtus,lgierth/virtus,JustMikey/virtus,baojjeu/virtus,kristianmandrup/virtus,macressler/virtus,nuclearsandwich/virtus,reevoo/virtus,mallikarjunayaddala/virtus,solnic/virtus,hapiben/virtus