Add a Sinatra app
Add Rakefile for the router
Set a Cache-Control header of 1 hour
Remove compile.sh script

This script was used to compile the service manual into the
design principles app. It is no longer needed.
Add search to the service manual

This includes a bit of duplication from the regular Jekyll service
manual, but it's all contained in the _search directory. As explained
in that README, I believe this is due to the way Jekyll implements
Liquid.

Bump the version of GDS API adapters because the version I included
from the design-principles app is out of date.
Add Rummager job to index the manual
Set Encoding to UTF-8

Liquid needs the encoding to be set to UTF-8 because of special
characters in places like the page title.
Merge pull request #428 from alphagov/add-sinatra-app

Add a Sinatra app