VOL-1554 Updated build to use LOCAL_PROTO for using local protos, and using a single base dockerfile

Change-Id: Ifa4ec6094c260a604918ccee75420bf328e647dd
diff --git a/.gitignore b/.gitignore
index 5fd0857..229b4bd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -63,6 +63,5 @@
 python/cli/.voltha_cli_history
 
 # Development versions of locally built libraries
-python/pyvoltha
-python/voltha-protos
+python/local_imports