1. update clientset, deepcopy using code-generator

2. add a dummy file tools.go to force "go mod vendor" to see
code-generator as dependencies
3. add a script to update CRD
4. add a README to document CRD updating steps
run go mod tidy
update README

vendor/github.com/emicklei/go-restful/coverage.sh

@@ -0,0 +1,2 @@
+go test -coverprofile=coverage.out
+go tool cover -html=coverage.out