feat: add cert-manager deployment for e2e test environments. (#28)

Adds Makefile target to pull the cert-manager deployment from the cert-manager project.

Makefile

@@ -212,3 +212,8 @@ $(CONTROLLER_GEN): $(LOCALBIN)
 envtest: $(ENVTEST) ## Download envtest-setup locally if necessary.
 $(ENVTEST): $(LOCALBIN)
 	test -s $(LOCALBIN)/setup-envtest || GOBIN=$(LOCALBIN) go install sigs.k8s.io/controller-runtime/tools/setup-envtest@latest
+
+config/certmanager-deployment/certmanager-deployment.yaml: ## Download the cert-manager deployment
+	test -s $@ || curl -L -o $@ \
+  		https://github.com/cert-manager/cert-manager/releases/download/v1.9.1/cert-manager.yaml
+

config/certmanager-deployment/.gitignore

@@ -0,0 +1,2 @@
+cert-manager.yaml
+certmanager-deployment.yaml

config/certmanager-deployment/README

@@ -0,0 +1,10 @@
+The Cert Manager is used during end-to-end tests to distribute the
+mutual TLS authentication certs used between the cloud-sql-proxy-operator
+and the kubernetes API. This is only used during E2E tests. cert-managger is not
+distributed as part of this operator.
+
+The Makefile will download an appropriate file to this directory from
+the certmanager website. This file should not be added to git.
+
+See: https://github.com/cert-manager/cert-manager
+