Run pep8 job in-repo

We removed the pep8 job from project-config, let's add
it back to our local .zuul.yaml.

Depends-On: https://review.opendev.org/714516
Change-Id: I5a9a65569e4103914e64a09c47104d0e3d7c5fe1
diff --git a/.zuul.yaml b/.zuul.yaml
index 1c4b793..6107d2f 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -2,6 +2,8 @@
     check:
       jobs:
         - gerritlib-jeepyb-integration
+        - tox-pep8
     gate:
       jobs:
         - gerritlib-jeepyb-integration
+        - tox-pep8