Required environmental variable:
SECRET_KEY: used for shared key authentication
Sample usages:
curl -d "url=https://groverwebdesign.com/&key=MYSECRETKEY" -X POST http://localhost:3000/web/submit/curl -d "url=https://groverwebdesign.com/&key=MYSECRETKEY&callback_url=http://httpbin.org/post" -X POST http://localhost:3000/api/submit/async/