build: add Zuul check pipeline

This pipeline checks the extension with |web-ext lint|.

Change-Id: I3bce686ff33fcbd24c0857da17eccd12458ed2ec
diff --git a/playbooks/lint/run.yaml b/playbooks/lint/run.yaml
new file mode 100644
index 0000000..70cd9fb
--- /dev/null
+++ b/playbooks/lint/run.yaml
@@ -0,0 +1,6 @@
+- hosts: all
+  roles:
+    - role: build-extension
+      make_target: test-extension
+    - role: web-ext-lint
+      source_dir: "src"