Enable black and pylint in tox.ini

Change-Id: I1571ce8b1a32aa67be1ada2864233c6f5ce9616b
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/osm_policy_module/common/mon_client.py b/osm_policy_module/common/mon_client.py
index b8c3779..1d498c2 100644
--- a/osm_policy_module/common/mon_client.py
+++ b/osm_policy_module/common/mon_client.py
@@ -53,7 +53,7 @@
         threshold: int,
         operation: str,
         statistic: str = "AVERAGE",
-        action: str = '',
+        action: str = "",
     ):
         cor_id = random.randint(1, 10e7)
         msg = self._build_create_alarm_payload(