Adding cover to tox.ini default envs

Change-Id: I258ebfa6fca69ff3f39e90230743ccce3c66890f
Signed-off-by: sousaedu <eduardo.sousa@canonical.com>
diff --git a/tox.ini b/tox.ini
index 61f96bd..990ab9b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,7 +16,7 @@
 #######################################################################################
 
 [tox]
-envlist = black, flake8, pylint, safety
+envlist = black, cover, flake8, pylint, safety
 
 [tox:jenkins]
 toxworkdir = /tmp/.tox