Failed outgoing calls need more pass through info

[edjez]

Expected: More detail on why twilio failed to deliver a call:

Obtained: "Error"

Example:

Call log #799728

Started: July 18, 2016, 15:45:12 (UTC)
Finished: July 18, 2016, 15:45:12 (UTC)
Duration: less than 5 seconds
Phone number: 212643863853
Direction: Outgoing
Channel: RTI Demo Twilio (830) 854-3211
Schedule: 24x7
Project: NCD Survey Demonstration
State: Failed
Failure information: Error.

[edjez]

For example, just enough more info could be a call ID to be able to find in the Twilio dashboard.
(In this particular case however, it seems the issue was not in twilio, so opening a different issue to deal with the instance and leave this issue as addressing the general need for more tshooting info)

[edjez]

For Skype channels, the error information seems much more adequate:

[mmuller]

Ok in version 3.0-pre2