Take all requests and copy them to different URLs.
Can add custom headers or change the HTTP method.
WEBHOOK_MULTIPLEXER_URLS="https://echo-api.3scale.net" rackup
WEBHOOK_MULTIPLEXER_URLS="https://echo-api.3scale.net;http://echo-api.3scale.net" rackup
WEBHOOK_MULTIPLEXER_URLS="GET,https://echo-api.3scale.net,Authentication: Bearer somekey" rackup
WEBHOOK_MULTIPLEXER_URLS="GET,https://echo-api.3scale.net,Authentication: Bearer somekey;POST,https://echo-api.3scale.net" rackup
heroku config:set WEBHOOK_MULTIPLEXER_URLS="http://requestb.in/18igo571;PUT,http://requestb.in/18igo571"
git push heroku master