Starting onos-1.6 support branch

Change-Id: I4d9d7052661480f6c1f607ada1c03534f0ec5156

@@ -3,4 +3,4 @@ host=gerrit.onosproject.org
 port=29418
 project=onos.git
 defaultremote=origin
-defaultbranch=master
+defaultbranch=onos-1.6

@@ -21,7 +21,7 @@ ENV PATH $PATH:$KARAF_ROOT/bin
 #Download and Build ONOS
 WORKDIR /src
 RUN     apt-get update && apt-get install -y python maven git curl oracle-java8-installer oracle-java8-set-default && \
-        git clone https://github.com/opennetworkinglab/onos.git && cd onos && \
+        git clone https://github.com/opennetworkinglab/onos.git && cd onos && git checkout onos-1.6 && \
         mkdir -p /root/Downloads && \
         mvn clean install && \
         tools/build/onos-package && \