Rework remote-setup.rb to use ansible about doorbot-setup HOT 2 CLOSED

Have set up the Ansible scaffolding to make a start on this over on the branch https://github.com/DoESLiverpool/doorbot-setup/tree/feature/18-move-to-ansible

At present all it'll do is set the Pi's name to doorbot and install git and ruby. There's a "base-doorbot" role which is where most of the setup steps will live, then the "install web browser, etc. for doorbot1" and "set up Kindle integration on doorbot3" can be layered on top (either as new roles, or just steps for the relevant doorbot in doorbot.yml)

I'm not 100% sure how to set it up, but it should be possible to set up groups of computers in the hosts file (I think) to allow us to then specify which doorbot we're building.
Need to move the rest of the things-that-need-installing into

from doorbot-setup.

The doorbot1 script is finished and pushed to the branch. At present the "wait_for" step near the end has the Pi's IP address hard-coded, as I hadn't managed to get it working with the ansible variables (it should be something like "{{ ansible_host }}"

However, apart from that, doorbot1 is back up and running.

We need to add the config for doorbots 2 and 3 still.

from doorbot-setup.