[#5322] (#5322) Remove spec file that adds little value and causes failures

spec/integration/indirector/rest_spec.rb has been deleted in puppet’s
next branch because it was found that the things being tested were
already covered in spec/unit/network/http/*. Also, the tests being
deleted were so overly mocked they weren’t testing much, and firing up
webrick as part of the tests was slow and causes intermittent failures
on Hudson.

This was discussed on the dev mailing list in the really long thread "No
puppet developer patches to the puppet-dev list".

Reviewed-by: Jesse Wolfe <jesse@puppetlabs.com>