CI: Generate ARA HTML

Since move to Swift ARA database does not render server-side,
let's make it render HTML locally as suggested.

Change-Id: I1190526c02d1f312d5284544d6e5be433dd839fa

tests/post.yml

@@ -67,4 +67,15 @@
             src: "{{ ansible_env.HOME }}/.ara/ansible.sqlite"
             dest: "{{ zuul.executor.log_root }}/{{ inventory_hostname }}/ara-report/"
             mode: pull
+
+        - name: Generate HTML from ARA database
+          command: "ara generate html {{ ansible_env.HOME }}/ara-html"
+          environment:
+            ARA_DATABASE: "sqlite:///{{ ansible_env.HOME }}/.ara/ansible.sqlite"
+
+        - name: Download ARA HTML
+          synchronize:
+            src: "{{ ansible_env.HOME }}/ara-html"
+            dest: "{{ zuul.executor.log_root }}/{{ inventory_hostname }}/ara-report/"
+            mode: pull
       when: ara_stat_result.stat.exists