Courtfinder controller redesigned

Removing the test data from the controller, which should have not been
in the controller in the first place, as it made the whole controller
more complex than required.
Further tweaks to the courtfinder controller

Getting the specs to pass as there are still issues and failures.
Spec fix for court address lookup
Courtfinder works with Postcode picker

Added the required Courtfinder stubs in order to get the Postcode picker
specs to pass.
Courtfinder stubbed out accross the specs

All the examples pass.
de-jsonify that which needs to be de-jsonified

There was mix and match of stubbed data that didn't need to be returned
as JSON. Stephen helpfully fixed it. I owe him a meal at the Korean
restaurant.
Long line clean up as per HoundCI warning
Added parentheses around method parameters

As per HoundCI warning
Hash syntax fix

As per HoundCI warning
Indentation fix
Line length fix
Indentation fix, for style
Indentation fix
Changed block from curly braces to 'do...end'
Indentation fix
Line shortening to comply with the style guide
Indentation fix for HoundCI
Indentation fix, again
Merge pull request #563 from ministryofjustice/stub-away

Fix for the exception for Courtfinder integration
updated govuk_frontend_toolkit; and added govuk_elements gem (not released yet)