bump STARR to 2.12.0-RC1
bump STARR to 2.12.0-RC1

shimib/scala,felixmulder/scala,lrytz/scala,lrytz/scala,slothspot/scala,slothspot/scala,shimib/scala,shimib/scala,shimib/scala,felixmulder/scala,felixmulder/scala,martijnhoekstra/scala,slothspot/scala,slothspot/scala,slothspot/scala,slothspot/scala,scala/scala,lrytz/scala,jvican/scala,lrytz/scala,jvican/scala,felixmulder/scala,lrytz/scala,jvican/scala,scala/scala,shimib/scala,scala/scala,martijnhoekstra/scala,scala/scala,martijnhoekstra/scala,scala/scala,martijnhoekstra/scala,martijnhoekstra/scala,felixmulder/scala,shimib/scala,martijnhoekstra/scala,jvican/scala,jvican/scala,jvican/scala,felixmulder/scala,jvican/scala,scala/scala,felixmulder/scala,slothspot/scala,lrytz/scala