Check signature of webhook

[vincvan]

It's straightforward, when setting up the controller manually, but I can not find how to check the signature of the webhook, when using the stripe-rails webhook implementation.

[tansengming]

so we don't actually check the signature, instead we chose to retrieve the event from Stripe to prove it's validity:

https://github.com/Everapps/stripe-rails/blob/0d78ff5ee41ad09abf38d8917243f69ac1cd24c0/app/models/stripe/event_dispatch.rb#L11-L18

that's why you can't find any signature checking code in the gem.

[tansengming]

just a note that we've added signature validation thanks to #125