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/.gitignore b/.gitignore
index 0f7b7b3..e380d44 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,3 +14,8 @@
 # Ansible
 ansible/*.retry
 
+# Virtualenv
+venv
+
+# Temp data dir for testing
+tmp