Update the jenkins worker to use the mongo role.

The common role also has to be included because vars that were previously being set in group_vars_all are now in
the slimmed down common.

playbooks/jenkins_worker.yml

@@ -6,5 +6,10 @@
   hosts: jenkins_worker
   sudo: True
   gather_facts: True
+  vars:
+      COMMON_DATA_DIR: '/mnt'
+      COMMON_LOG_DIR: '/mnt/log'
   roles:
+    - common
+    - mongo
     - jenkins_worker

playbooks/roles/jenkins_worker/defaults/main.yml

@@ -22,7 +22,6 @@ jenkins_debian_pkgs:
     - libgeos-dev
     - libmysqlclient-dev
     - libxslt1-dev
-    - mongodb
     - npm
     - pkg-config
     - python2.7