Voice API v2.2.0

Fixes

  • Split POST /calls in to a oneOf for answer_url and ncco options
  • Split PUT /calls/:id in to a oneOf for transfer with answer_url and ncco options, plus hangup, mute, unmute, earmuff, unearmuff
  • Remove dtmfAnswer from the from option when placing a call
  • Fix examples for ncco, event_url and answer_url