Add google/gnxi as submodule

.gitmodules

@@ -6,3 +6,6 @@
 	path = models/openconfig
 	url = https://github.com/openconfig/public.git
     branch = master
+[submodule "forks/google"]
+	path = forks/google
+	url = https://github.com/google/gnxi

.golangci.yml

@@ -9,6 +9,7 @@ run:
         - controller/test
         - controller/mocks
         - models/generated/openconfig
+        - forks/
     skip-dirs-default: true
     skip-files:
         - http.go

google @ cd6b043b

+Subproject commit cd6b043b7fd0b36a25a27289c8d719ee19833329