Add task plugin to the check pipeline

Change-Id: I4069265a93214bc217c3e8e73221ed740e86aa59
diff --git a/zuul.d/projects.yaml b/zuul.d/projects.yaml
index 37a513a..76e1d23 100644
--- a/zuul.d/projects.yaml
+++ b/zuul.d/projects.yaml
@@ -217,3 +217,9 @@
     check:
       jobs:
         - gerrit-plugin-build
+
+- project:
+    name: plugins/task
+    check:
+      jobs:
+        - gerrit-plugin-build