Replace Transactions Explorer global 301

These mappings can't work with the Redirector, but they can work with Bouncer
which is where we'll put them.
Merge pull request #454 from rjc123/master

Updated mappings for offdocs
Fix broken Transactions Explorer mappings
Add transactionalservices.alphagov as an alias

I'm not sure if we'll use it yet, but as it definitely redirects
it can't hurt to be in here.
Merge pull request #456 from rjc123/master

BIS BRDO assets
Configure berr.gov as alias to bis.gov
Merge pull request #457 from rjc123/newsites

Configure berr.gov as alias to bis.gov
Remove redundant mapping

This was handled by having this domain aliased.
Remove remaining FCO tests

(for sites now handled by Bouncer)
Merge pull request #458 from alphagov/remove-remaining-fco-tests

Remove remaining FCO tests
Add Transactions Explorer tests

These cover the two variations on query params we use.
Merge pull request #455 from alphagov/replace_transactions_explorer_global_redirect_with_mappings

Replace Transactions Explorer global redirect with mappings
Move transactionsexplorer to Transition
Merge pull request #459 from alphagov/move_transactionsexplorer_to_transition

Move transactionsexplorer to Transition
Add G-Cloud site
Merge pull request #460 from alphagov/add_g_cloud

Add G-Cloud site