Add oauth plugin to check pipeline

This adds the oauth plugin to the check pipeline.

Change-Id: I3ea867e09e74f6666c25d6f68a508f9de14910a9
Depends-On: https://gerrit-review.googlesource.com/273472

zuul.d/projects.yaml

diff --git a/zuul.d/projects.yaml b/zuul.d/projects.yaml
index ae2f434..977b1ee 100644
--- a/zuul.d/projects.yaml
+++ b/zuul.d/projects.yaml
@@ -85,3 +85,9 @@
     check:
       jobs:
         - gerrit-plugin-build
+
+- project:
+    name: plugins/oauth
+    check:
+      jobs:
+        - gerrit-plugin-build