Fix flake8, black and pylint errors in code

Change-Id: Ic03f4d31e2ba9801be20d3679bd5749948cab39d
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/osm_ee/exceptions.py b/osm_ee/exceptions.py
index 4829197..a99399d 100644
--- a/osm_ee/exceptions.py
+++ b/osm_ee/exceptions.py
@@ -20,8 +20,10 @@
 # contact with: nfvlabs@tid.es
 ##
 
+
 class ExecEnvException(Exception):
     """Exception thrown by the EE if the actions can't be invoked or there is any generic error"""
 
+
 class VnfException(Exception):
-    """Exception thrown by the Vnf EE code in case of error"""
\ No newline at end of file
+    """Exception thrown by the Vnf EE code in case of error"""