Provider integration documentation fix.

I've been working on the facebook/google integration and have found a few minor mistakes with the format of requests and responses for that part in the REST documentation.

There were some places that were missing quotation marks or commas, and basically I modified requests to be CURL-friendly. One thing i absolutely love about the stormpath REST documentation is the part where requests are written as CURL requests. Then I can just easily copy paste them into my terminal and run them before I start working on new features in the Ruby SDK.

Also, there was a mistake with the request for creating a new facebook directory. It's url didn't hold an 'expand=provider' query string, but the response had a an expanded provider resource. On the other hand, the google one was okay. If you wish to have them both expanded, or not, i can modify this pull request to reflect that.