remove wrtc, can be mocked for tests (#180)

src/setupTests.ts

@@ -5,8 +5,6 @@
 import '@testing-library/jest-dom'
 import WebSocket from 'ws';
 import 'setimmediate'
-// @ts-ignore
-import wrtc from 'wrtc'
 
 class WebsocketWrapper {
   constructor(url: string) {
@@ -18,6 +16,39 @@ class WebsocketWrapper {
   }
 }
 
-global.RTCPeerConnection = wrtc.RTCPeerConnection
+class MockRTCPeerConnection {
+  constructor() {
+  }
+  createDataChannel() {
+    return
+  }
+  setRemoteDescription() {
+    return Promise.resolve()
+  }
+  setConfiguration() {
+    return Promise.resolve()
+  }
+  addEventListener() {
+    return Promise.resolve()
+  }
+  get localDescription() {
+    return Promise.resolve()
+  }
+  addTransceiver() {
+    return Promise.resolve()
+  }
+  createOffer() {
+    return Promise.resolve()
+  }
+  setLocalDescription() {
+    return Promise.resolve()
+  }
+  close() {
+    return Promise.resolve()
+  }
+}
+
+// @ts-ignore
+global.RTCPeerConnection = MockRTCPeerConnection
 // @ts-ignore
 global.WebSocket = WebsocketWrapper