validate that object name adheres to RFC 1123 for flux create commands

Signed-off-by: Somtochi Onyekwere <somtochionyekwere@gmail.com>

cmd/flux/create_secret_git_test.go

@@ -13,7 +13,7 @@ func TestCreateGitSecret(t *testing.T) {
 		{
 			name:   "no args",
 			args:   "create secret git",
-			assert: assertError("secret name is required"),
+			assert: assertError("name is required"),
 		},
 		{
 			name:   "basic secret",