support Configuration provisioning of devices

According with https://github.com/telefonicaid/sigfox-iotagent/blob/master/README.md#basic-usage
NOTE: this first version doesn't support Configuration provisioning, so each device must be provisioned individually.

https://github.com/telefonicaid/sigfox-iotagent/blob/master/lib/sigfoxHandlers.js#L133