Feature/siprec server (#143)

* fixes from testing

* modify Task#exec to take resources as an object rather than argument list

* pass 2 endpoints to Transcribe when invoked in a SipRec call session

* logging

* change siprec invite to sendrecv just so freeswitch does not try to reinvite (TODO: block outgoing media at rtpengine)

* Config: when enabling recording, block until siprec dialog is established

* missed play verb in commit 031c79d

* linting

* bugfix: get final transcript in siprec call

lib/utils/constants.json

@@ -29,6 +29,7 @@
     "Tag": "tag",
     "Transcribe": "transcribe"
   },
+  "AllowedSipRecVerbs": ["config", "gather", "transcribe", "listen"],
   "CallStatus": {
     "Trying": "trying",
     "Ringing": "ringing",