Lint and fix renos

One of the renos was causing issues due to a duplicated id.
This change makes tox doc8 env lint renos and fixes
the offending reno.

Change-Id: Id3ae6e144b4261c97726cdec172ea9bef093de9e

tox.ini

@@ -108,6 +108,7 @@ exclude = .eggs,.git,.tox,doc
 deps = {[testenv:linters]deps}
 commands =
   doc8 doc/source
+  reno lint
   doc8 -e '.yaml' releasenotes/notes/
 
 [testenv:bashate]