[codespell] Adding CI target for Tox Codespell

Third in a series of commits to add Codespell to Ironic Repos. This commit adds the Tox Target to CI

A future commit could potentially add a git-blame-ignore-revs file if their are lots of spelling mistakes that could clutter git blame.

Change-Id: Iad0de1da0aa600f92b765449bcfeee2f2c69759d

.zuul.yaml

@@ -21,6 +21,13 @@
         horizon: true
       tox_envlist: integration
 
+- job:
+    name: ironic-ui-tox-codespell
+    parent: openstack-tox
+    timeout: 7200
+    vars:
+      tox_envlist: codespell
+
 - project:
     templates:
       - check-requirements
@@ -34,3 +41,5 @@
       jobs:
         - ironic-ui-integration-tests:
             voting: false
+        - ironic-ui-tox-codespell:
+            voting: false