Bug 1045966 — Add a tool that let us validate the Service Provider.

https://bugzilla.mozilla.org/show_bug.cgi?id=1045966
We could probably but the goal was to propose something and let the user configure some options with regards to the Service Provider. But it is clear that here we are targeting loop. `-d '{\"simplePushURL\": \"http://httpbin.org/deny\"}'`