Use Excon.stub instead of Webmock.
Use Excon.stub instead of Webmock.

Couldn't figure out why Webmock refused to apply to the V3 API calls
but works fine for the V2 ones, but Excon.stub works.

heroku/heroku,duypq94/heroku,Faisalawanisee/heroku,sancopanco/heroku,rkh/heroku,macedo/heroku,macedo/heroku,duypq94/heroku,rkh/heroku,vcgato29/heroku,sancopanco/heroku,vcgato29/heroku,greeca0204/heroku,greeca0204/heroku,sancopanco/heroku,dickeyxxx/heroku,rkh/heroku,Faisalawanisee/heroku,duypq94/heroku,greeca0204/heroku,Faisalawanisee/heroku,gregburek/heroku,heroku/heroku,macedo/heroku,dickeyxxx/heroku,gregburek/heroku,dickeyxxx/heroku,heroku/heroku,vcgato29/heroku,gregburek/heroku