Makefile: Also push :latest for flannel-git

Makefile

@@ -159,6 +159,8 @@ docker-push-all:
 
 flannel-git:
 	ARCH=amd64 REGISTRY=quay.io/coreos/flannel-git make clean dist/flanneld-$(TAG)-amd64.docker docker-push
+	docker build -f Dockerfile.amd64 -t quay.io/coreos/flannel-git .
+	docker push quay.io/coreos/flannel-git
 	ARCH=arm REGISTRY=quay.io/coreos/flannel-git make clean dist/flanneld-$(TAG)-arm.docker docker-push
 	ARCH=arm64 REGISTRY=quay.io/coreos/flannel-git make clean dist/flanneld-$(TAG)-arm64.docker docker-push
 	ARCH=ppc64le REGISTRY=quay.io/coreos/flannel-git make clean dist/flanneld-$(TAG)-ppc64le.docker docker-push