Redesign of Podder.

Podder now only listens to events from the docker
api. Docker event api will use a callback mechanism
to take action when a container is started or stopped.

Adding Dockerfile for podder and an entry into the
compose file.

Change-Id: Ib5735078a69eab3af6076af94bc697ab3e82a239
diff --git a/Makefile b/Makefile
index 138eea9..6b58405 100644
--- a/Makefile
+++ b/Makefile
@@ -77,6 +77,7 @@
 	docker build -t cord/voltha -f Dockerfile.voltha .
 	docker build -t cord/chameleon -f Dockerfile.chameleon .
 	docker build -t cord/ofagent -f Dockerfile.ofagent .
+	docker build -t cord/podder -f Dockerfile.podder .
 
 docker-base:
 	docker build -t cord/voltha-base -f Dockerfile.base .