Add avatars-external plugin checker

Change-Id: I88dcb53da8110faacc66a41b4d752bf0f09e7345
diff --git a/checkers.yaml b/checkers.yaml
index a9ee7a2..ceec518 100644
--- a/checkers.yaml
+++ b/checkers.yaml
@@ -96,6 +96,11 @@
     name: "Zuul Check Pipeline"
     description: "Run Zuul jobs on new patchsets"
 
+  - uuid: "zuul-check:plugins_avatars-external"
+    repository: "plugins/avatars-external"
+    name: "Zuul Check Pipeline"
+    description: "Run Zuul jobs on new patchsets"
+
   - uuid: "zuul-check:plugins_batch"
     repository: "plugins/batch"
     name: "Zuul Check Pipeline"
diff --git a/zuul/main.yaml b/zuul/main.yaml
index f58f499..e43e2c0 100644
--- a/zuul/main.yaml
+++ b/zuul/main.yaml
@@ -31,6 +31,7 @@
           - polymer-bridges
           # All of the rest of the projects, alphabetically sorted.
           - plugins/admin-console
+          - plugins/avatars-external
           - plugins/batch
           - plugins/changemessage
           - plugins/checks