Escape segments of Pact URL
Escape segments of Pact URL

Previously if the value ENV['GDS_API_PACT_VERSION'] contained a
slash the Pact URL would 404, usage of ERB::Util.url_encode 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 url encoding all along.

ERB::Util.url_encode has been used over CGI.escape as the former changes
spaces to %20 whereas the latter has + which does not work in paths.

alphagov/publishing-api,alphagov/publishing-api