Add web-ext-lint job report to the log folder

- Add fetch-web-ext-lint role, which copies the web-ext-lint report to
  the log folder.

Changes in the web-ext-lint job:
- Change the main playbook so the lint report is saved in a file called
  web-ext-lint.txt (so it can fetched later on).
- Add a post playbook which calls the fetch-web-ext-lint role.
- Add a description to the job.

Change-Id: Ifc2ef60084ecc33087e5ce2761ad91d84e7eff3c
diff --git a/roles/fetch-web-ext-lint/tasks/main.yaml b/roles/fetch-web-ext-lint/tasks/main.yaml
new file mode 100644
index 0000000..8a81b51
--- /dev/null
+++ b/roles/fetch-web-ext-lint/tasks/main.yaml
@@ -0,0 +1,14 @@
+- name: Is there a web-ext-lint.txt
+  register: stat_wel_txt
+  stat:
+    path: "{{ zuul.project.src_dir }}"
+
+- name: Store on executor
+  when: stat_wel_txt.stat.exists
+  synchronize:
+    mode: pull
+    src: "{{ zuul.project.src_dir }}/web-ext-lint.txt"
+    dest: "{{ zuul.executor.log_root }}/web-ext-lint.txt"
+    verify_host: true
+    owner: no
+    group: no