Add ref-protection plugin checker

Change-Id: I5962c6ccb9d6bdfd17e8ecefdc295b7385988931

checkers.yaml

diff --git a/checkers.yaml b/checkers.yaml
index 204d1ff..dfb06e2 100644
--- a/checkers.yaml
+++ b/checkers.yaml
@@ -236,6 +236,11 @@
     name: "Zuul Check Pipeline"
     description: "Run Zuul jobs on new patchsets"
 
+  - uuid: "zuul-check:plugins_ref-protection"
+    repository: "plugins/ref-protection"
+    name: "Zuul Check Pipeline"
+    description: "Run Zuul jobs on new patchsets"
+
   - uuid: "zuul-check:plugins_rename-project"
     repository: "plugins/rename-project"
     name: "Zuul Check Pipeline"

zuul/main.yaml

diff --git a/zuul/main.yaml b/zuul/main.yaml
index 5954cf8..7e63875 100644
--- a/zuul/main.yaml
+++ b/zuul/main.yaml
@@ -60,6 +60,7 @@
           - plugins/rabbitmq
           - plugins/rate-limiter
           - plugins/readonly
+          - plugins/ref-protection
           - plugins/rename-project
           - plugins/reviewers
           - plugins/saml