Make Facebook and Google contracts

[nanaknihal]

To do this, you just have to deploy a contract with different constructor arguments. You find e and n from the JWK-formatted public key of Facebook or Google. You will need to find the bottombread and topbread from an actual JWT -- see which characters always surround the credential of interest, e.g. email or facebook username, so that we can be sure anything sandwiched between them is the credential we are interested in.

[nanaknihal]

Google done, not facebook. Facebook seemed to use HMAC?? Worth revisiting to try to find asymmetric signature for facebook, even if it means getting an access token