Move semaphore branch build steps into Makefile.
Move semaphore branch build steps into Makefile.

projectcalico/calico-containers,projectcalico/calico-docker,insequent/calico-docker,projectcalico/calico-docker,projectcalico/calico-containers,Metaswitch/calico-docker,insequent/calico-docker,caseydavenport/calico-containers,caseydavenport/calico-containers,Metaswitch/calico-docker,caseydavenport/calico-containers,projectcalico/calico-containers,caseydavenport/calico-docker,caseydavenport/calico-docker