VOL-1460 Updated core to use voltha-protos instead of local protos
Moved protos to python directory in order to maintain functionaly of containers built there.
Added capability to do local builds of protos
Added instructions on running dep ensure for getting protos.
Updated github.com/golang/protobuf version to v1.3.1

Change-Id: Ia6ef55f07f0d5dcb5b750d7c37b21b71db85bfc4
diff --git a/docker/Dockerfile.rw_core b/docker/Dockerfile.rw_core
index 714ead7..8081beb 100644
--- a/docker/Dockerfile.rw_core
+++ b/docker/Dockerfile.rw_core
@@ -11,9 +11,9 @@
 RUN go get google.golang.org/genproto/googleapis/api/annotations
 
 # Prepare directory structure
-RUN ["mkdir", "-p", "/src", "src/protos"]
+RUN ["mkdir", "-p", "/src"]
 RUN ["mkdir", "-p", "$GOPATH/src", "$GOPATH/pkg", "$GOPATH/bin"]
-RUN ["mkdir", "-p", "$GOPATH/src/github.com/opencord/voltha/protos/go"]
+RUN ["mkdir", "-p", "$GOPATH/src/github.com/opencord/voltha-go"]
 
 WORKDIR $GOPATH/src/github.com/opencord/voltha-go
 
@@ -24,17 +24,6 @@
 ADD kafka ./kafka
 ADD vendor ./vendor
 
-# Install the protoc-gen-go
-RUN go install ./vendor/github.com/golang/protobuf/protoc-gen-go
-
-# Copy required proto files
-# ... VOLTHA proos
-ADD protos/*.proto /src/protos/
-ADD protos/scripts/* /src/protos/
-
-# Compile protobuf files
-RUN sh /src/protos/build_protos.sh /src/protos
-
 # Build rw_core
 RUN cd rw_core && go build -o /src/rw_core