Initial refactor of N2VC

- Add libjuju.py to encapsulate all code related with the communication using libjuju
- Replace juju_observer with juju_watcher
- Add utils with some utilities like EntityType, FinalStatus, and JujuStatusToOSM

Change-Id: I5d46ad65d6ed37b49bf2504209bfdd46d1b5a7e4
Signed-off-by: David Garcia <david.garcia@canonical.com>
diff --git a/tox.ini b/tox.ini
index 490d03e..bc316e1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -65,7 +65,7 @@
 
 [flake8]
 # W503 is invalid PEP-8
-max-line-length = 88
+max-line-length = 100
 show-source = True
 ignore = W503,E203
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build,devops_stages/*,.rst