First draft of search functionality

Driven by talking to the content service - you'll need to have that running locally on port 8080 but if not can override that with MAS_CONTENT_SERVICE_URL or hard coding the fake repository in the core.rb initializer.

As mentioned, we also have multiple repositories - the plumbed in one driven by the content service, a fake one for manual testing (automated tests use vcr) and another one driven by an api end point initially exposed in the public website.

We'll probably want some tweaking on the behaviour of the search when there's no query or no results found.