Add the ability to create groups

Change-Id: Ia3afd1751bf822a7efd706aa029dbed079e7c026
diff --git a/defaults/main.yml b/defaults/main.yml
index a79f112..51fcd90 100644
--- a/defaults/main.yml
+++ b/defaults/main.yml
@@ -7,3 +7,5 @@
 userlist: []
 
 users_sudoers: []
+
+users_groups: []