Support for Ansible 2.x

[WerlingM]

When provisioning the server with Ansible 2.0.0.1 installed I get an error:
TASK [web : Run Django database migrations] ************************************ [DEPRECATION WARNING]: Using bare variables for environment is deprecated. Update your playbooks so that the environment value uses the full variable syntax ('{{foo}}'). This feature will be removed in a future release. Deprecation warnings can be disabled by setting deprecation_warnings=False in ansible.cfg. fatal: [default]: FAILED! => {"failed": true, "msg": "ERROR! environment must be a dictionary, received django_environment (<class 'ansible.parsing.yaml.objects.AnsibleUnicode'>)"}

RUNNING HANDLER [memcached : restart memcached] ********************************

Rolling back to Ansible 1.9.4 (pip install "ansible==1.9.4) fixes the issue.