Add code-owners checker

This creates a new checker for the code-owners plugin and adds it
to Zuul.

Change-Id: I411ab354fa44deeb56014533dbaa5d2dcd3ad0a6
diff --git a/checkers.yaml b/checkers.yaml
index daa156e..54cf486 100644
--- a/checkers.yaml
+++ b/checkers.yaml
@@ -88,3 +88,10 @@
     repository: "plugins/webhooks"
     name: "Zuul Check Pipeline"
     description: "Run Zuul jobs on new patchsets"
+
+# Other plugins:
+
+  - uuid: "zuul-check:plugins_code-owners"
+    repository: "plugins/code-owners"
+    name: "Zuul Check Pipeline"
+    description: "Run Zuul jobs on new patchsets"
diff --git a/zuul/main.yaml b/zuul/main.yaml
index 3726f43..93474a7 100644
--- a/zuul/main.yaml
+++ b/zuul/main.yaml
@@ -14,7 +14,7 @@
           # preference.
           - zuul/jobs
           - zuul/ops
-          # All of the rest of the projects, alphabetically sorted.
+          # All of the core projects, alphabetically sorted.
           - gerrit
           - jgit
           - plugins/checks
@@ -30,3 +30,5 @@
           - plugins/singleusergroup
           - plugins/webhooks
           - polymer-bridges
+          # All of the rest of the projects, alphabetically sorted.
+          - plugins/code-owners