Escape segments of Pact URL
Escape segments of Pact URL

Previously if the value ENV['PUBLISHING_API_PACT_VERSION'] contained a
slash the Pact URL would 404, usage of CGI.escape will percent encode
non URI characters.

The usage of URI.escape has been updated in the url variable also as I
think the original author meant the effects of CGI.escape all along.

alphagov/content-store,alphagov/content-store