Add Make targets that push to development clusters

Author: cbandy

Makefile

@@ -141,6 +141,13 @@ build: ## Build a postgres-operator image
 		--label org.opencontainers.image.title='Crunchy PostgreSQL Operator' \
 		.
 
+build-k3d: image.tar ; $(or $(K3D),k3d) image import $<
+build-kind: image.tar ; $(or $(KIND),kind) load image-archive $<
+build-minikube: image.tar ; $(or $(MINIKUBE),minikube) image load $<
+
+image.tar: build
+	$(BUILDAH) push localhost/postgres-operator oci-archive:$@:localhost/postgres-operator:latest
+
 ##@ Test
 
 .PHONY: check