PLT-3412 WebRTC Server side & System Console (#3706)

* WebRTC Server side

* WebRTC System Console

* Consistency on variable names

* Add turn and stun uri validation

api/webrtc_test.go

@@ -0,0 +1,18 @@
+// Copyright (c) 2016 Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package api
+
+import "testing"
+
+func TestWebrtcToken(t *testing.T) {
+	th := Setup().InitBasic()
+
+	if _, err := th.BasicClient.GetWebrtcToken(); err != nil {
+		if err.Id != "api.webrtc.not_available.app_error" {
+			t.Fatal("Should have fail, webrtc not availble")
+		}
+	} else {
+		t.Fatal("Should have fail, webrtc not availble")
+	}
+}