Use code-generator to generate clientset/informer/lister (#1492)

To reduce maintenance effort and avoid writing duplicate informer code,
use code-generator to generate clientset/informer/lister code.

pkg/fission-cli/cmd/environment/get.go

@@ -52,7 +52,7 @@ func (opts *GetSubCommand) do(input cli.Input) error {
 
 	fmt.Fprintf(w, "%v\t%v\n", "NAME", "IMAGE")
 	fmt.Fprintf(w, "%v\t%v\n",
-		env.Metadata.Name, env.Spec.Runtime.Image)
+		env.ObjectMeta.Name, env.Spec.Runtime.Image)
 
 	w.Flush()
 	return nil