updated the onos-service start script to support specification of initial
applications to active and updated the docker image from CMD to entrypoint

Change-Id: I7d9d32ff4b756bc8834f7666473f3bca82812fc8
Signed-off-by: David K. Bainbridge <dbainbri@ciena.com>
diff --git a/tools/build/docker/Dockerfile b/tools/build/docker/Dockerfile
index 214c11c..fd61ad8 100644
--- a/tools/build/docker/Dockerfile
+++ b/tools/build/docker/Dockerfile
@@ -53,4 +53,4 @@
 
 # Get ready to run command
 WORKDIR /root/onos
-CMD ["./bin/onos-service"]
+ENTRYPOINT ["./bin/onos-service"]