Feature/minimal media anchoring (#12)

* feature: release media from freeswitch

* handle mute/unmute

* linting

* update dep

* support for relaying dtmf via SIP INFO to FS

* fix ci test

* handle outdial error

data/rtp-transcoding.json

@@ -3,5 +3,6 @@
   "DTLS": "off",
   "SDES": "off",
   "ICE": "remove",
+  "flags": ["media handover", "port latching"],
   "rtcp-mux": ["demux"]
 }

data/srtp-transcoding.json

@@ -3,7 +3,7 @@
     "transport-protocol": "UDP/TLS/RTP/SAVPF",
     "ICE": "force",
     "SDES": "off",
-    "flags": ["generate mid", "SDES-no", "media handover"],
+    "flags": ["generate mid", "SDES-no", "media handover", "port latching"],
     "rtcp-mux": ["require"]  
   },
   "teams": {