Update ReadME: Example dont work in current sails version

I tried with sails v0.10.0-rc7 and get the error:

    error: One of your models (Email) doesn't have a connection.
    error: Do you have a default `connection` in your `config/models.js` file?

Change connections to connection get this working. 

Also i have to put the file in api/models/ not in config/modules.