Define Bandwidth.Com API

This is the API for  http://bandwidth.com/. Their document is at https://catapult.inetwork.com/docs/
They are similar to Twilio. 

This API def is extract from [https://github.com/kureikain/bandwidth-php/tree/alpaca](https://github.com/kureikain/bandwidth-php/tree/alpaca).
I don't think this file is needed.