Delete tests for aka.bis.gov.uk

bis has been managed by transition for some time, and now that it
has fully transitioned we shouldn't need to test the aka domain anyway.
Delete popular tests for decc_og

This site has been managed by transition for some time.
Merge pull request #728 from alphagov/delete_aka_bis_tests

Delete tests for aka.bis.gov.uk
Merge pull request #729 from alphagov/delete_decc_og_popular_tests

Delete popular tests for decc_og
Replace piplink rule with individual mappings
Remove businesslink homepage and search rules and replace with mappings