Tidy up dead code

Now that the orgs and needs are imported via rake tasks:

organisations:import
needs:import

These legacy does not need to be here.
platform wording amends

things messed up in `20140421143815_platfrom_wording_changes`. Change wording:
`whitehall -> publisher`
`publisher -> whitehall`
Merge pull request #87 from bitzesty/platform-wording-amends

Swap the platforms around as they were previously migrated incorrectly
Merge pull request #85 from alphagov/remove_old_api_client

Tidy up dead code