Consul registration and kv interface added

Additional changes:
- Reworked command line parsing
- Added cleaner default handling, also reading certain environmen vars
- Many new options
- Docker compose file to start a consul + fluentd + voltha combo for
  testing purposes
diff --git a/Makefile b/Makefile
index fa2c0bd..4d586e2 100644
--- a/Makefile
+++ b/Makefile
@@ -40,8 +40,9 @@
 	find voltha -name '*.pyc' | xargs rm -f
 
 fetch:
-	docker pull consul
-	docker pull fluent/fluentd
+	docker pull consul:latest
+	docker pull fluent/fluentd:latest
+	docker pull gliderlabs/registrator:latest
 
 purge-venv:
 	rm -fr ${VENVDIR}