[wip] Use Ansible instead of a shell script to deploy the site from Jenkins.

Use it to manage the deployment and configuration of the node.js backend (#375) as well.
If I'm understanding this right, the idea is to have an upstart script to run the node process that processes the sponsorship form (i.e. `{{ backendroot }}/index.js`). Lets say we change the code in this `index.js` file. Wouldn't this service need to be restarted via `sudo service restart sponsorship-form` to pick up the changes? If so, when would that happen and which user would perform the restart?