build: add Zuul check pipeline

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

Change-Id: I3bce686ff33fcbd24c0857da17eccd12458ed2ec
diff --git a/roles/build-extension/tasks/main.yaml b/roles/build-extension/tasks/main.yaml
new file mode 100644
index 0000000..6ca0225
--- /dev/null
+++ b/roles/build-extension/tasks/main.yaml
@@ -0,0 +1,6 @@
+- name: Build extension
+  make:
+    chdir: "{{ zuul.project.src_dir }}"
+    target: "{{ make_target }}"
+  environment:
+    PATH: "{{ ansible_env.HOME }}/go/bin:/usr/local/go/bin:{{ ansible_env.PATH }}"