roles/taiga: Deploy Taiga project management app

The *taiga* role installs the three components of Taiga:

* taiga-back
* taiga-events
* taiga-front

*taiga-back* is a Python application. Its dependencies are installed via
`pip` in the *taiga* user's site-packages, and the application itself is
installed by unpacking the archive. *taiga-events* is a Node.js
application. Its dependencies are installed by `npm`, and is itself
installed by unpacking the archive. Finally, *taiga-front* is a
single-page browser application that is installed by unpacking the
archive, and served by Apache.

Taiga requires PostgreSQL and RabbitMQ.

roles/taiga/tasks/main.yml

@@ -0,0 +1,19 @@
+- import_tasks: postgresql.yml
+- import_tasks: rabbitmq.yml
+
+- import_tasks: taiga-back.yml
+- import_tasks: taiga-front.yml
+- import_tasks: taiga-events.yml
+
+- name: ensure apache is configured to serve taiga
+  copy:
+    src: taiga.httpd.conf
+    dest: /etc/httpd/conf.d/taiga.conf
+    mode: '0644'
+  notify:
+  - reload httpd
+- name: ensure selinux allows apache to proxy for taiga
+  seboolean:
+    name: httpd_can_network_connect
+    state: true
+    persistent: true