VOL-1460: Docker builds now use common base image.  Also Documentation Update.

Modified all docker files to use a base build that copies in vendor and
other common GOPATH items.  Then each dependant Dockerfile
uses the base and only copies in golang source needed to build.

Also grab updated lock file and vendor items missing (from a dep ensure)
for build to work.

Change-Id: I6047847c2c186a24d1f223b1a4dfab39ab381a92
diff --git a/docker/Dockerfile.arouterd b/docker/Dockerfile.arouterd
index f3c1dd3..2d5f139 100644
--- a/docker/Dockerfile.arouterd
+++ b/docker/Dockerfile.arouterd
@@ -3,37 +3,30 @@
 
 FROM base AS build-env
 
-
-# Copy files
-ADD rw_core $GOPATH/src/github.com/opencord/voltha-go/rw_core
-ADD common $GOPATH/src/github.com/opencord/voltha-go/common
-ADD db $GOPATH/src/github.com/opencord/voltha-go/db
-ADD kafka $GOPATH/src/github.com/opencord/voltha-go/kafka
-ADD afrouter $GOPATH/src/github.com/opencord/voltha-go/afrouter
-ADD arouterd $GOPATH/src/github.com/opencord/voltha-go/arouterd
-
-
-# Repeate here even if done in base file
-ADD afrouter/arouter.json /src
-
-#
-# Copy generated executables here
 WORKDIR $GOPATH/src/github.com/opencord/voltha-go
 
-# Compile protobuf files
-# Repeate here even if done in base file
-RUN go get google.golang.org/genproto/googleapis/api/annotations
+# Copy files
+COPY rw_core ./rw_core
+COPY afrouter ./afrouter
+COPY arouterd ./arouterd
 
-# Build rw_core
-RUN cd arouterd && go build -o /src/arouterd
+# Copy config
+RUN cp afrouter/arouter.json /build
+
+# Build
+RUN cd arouterd && go build -o /build/arouterd
+
 
 # -------------
 # Image creation stage
 
-FROM alpine:3.6
+FROM alpine:3.9
 
 # Set the working directory
 WORKDIR /app
 
 # Copy required files
-COPY --from=build-env /src/arouterd /app/
+COPY --from=build-env /build/arouterd /app/
+COPY --from=build-env /build/arouter.json /app/
+
+ENTRYPOINT ["/app/arouterd"]