fix(tests) Support Kubernetes >= 1.16

Operator use kind "CustomResourceDefinition" in version "apiextensions.k8s.io/v1"

Signed-off-by: Pierre Péronnet <pierre.peronnet@ovhcloud.com>

.github/workflows/tests.yml

@@ -75,7 +75,10 @@ jobs:
         # https://github.com/jetstack/cert-manager/tags
         certManager: ["0.12.0", "0.13.1", "0.14.2", "0.15.0-alpha.0"]
         # https://snapcraft.io/microk8s
-        k8sVersion: ["1.15", "1.16", "1.17"]
+        k8sVersion:
+        - "1.16"
+        - "1.17"
+        # - "1.18" # TODO check why Registry and RegistryCtl controllers tests fail
 
     steps: 
     - uses: actions/setup-go@v2

README.md

@@ -70,7 +70,7 @@ See [install documentation](https://github.com/goharbor/harbor-operator/blob/mas
 
 ### Supported platforms
 
-- [Kubernetes](https://kubernetes.io/docs/concepts/overview/kubernetes-api/) >= 1.15
+- [Kubernetes](https://kubernetes.io/docs/concepts/overview/kubernetes-api/) >= 1.16
 
 ### Harbor version