adding param for root_ebs_size

playbooks/library/ec2_local

@@ -185,7 +185,7 @@ options:
     default: 'present'
     aliases: []
   root_ebs_size:
-    version_added: "1.4"
+    version_added: "1.5"
     desription:
       - size of the root volume in gigabytes
       required: false
@@ -624,6 +624,7 @@ def main():
             instance_profile_name = dict(),
             instance_ids = dict(type='list'),
             state = dict(default='present'),
+            root_ebs_size = dict(default=None),
         )
     )