Remove basic auth from Whitehall admin API paths.
Remove basic auth from Whitehall admin API paths.

Whitehall is being given an admin API for triggering
reindexing, protected by GDS SSO.  The bearer token
clashes with the basic auth header, preventing
app to app communication and making manual usage
more difficult.
alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet