Move gunicorn install to common.

playbooks/roles/common/tasks/create_venv.yml

@@ -32,3 +32,9 @@
   tags:
   - venv_base
   - install
+
+- name:  pip install gunicorn
+  pip: name=gunicorn virtualenv="{{venv_dir}}" state=present
+  tags:
+  - gunicorn
+  - install

playbooks/roles/gunicorn/tasks/main.yml

 ---
-- name:  pip install gunicorn
-  pip: name=gunicorn virtualenv="{{venv_dir}}" state=present
-  tags:
-  - gunicorn
-  - install
 - name: creating edxapp upstart script
   sudo: True
   template: src=edxapp.conf.j2 dest=/etc/init/edxapp.conf owner=root group=root