[bugfix] get slack private groups member list back

srv/src/slack.js

@@ -110,7 +110,8 @@ Slack.prototype.connect = function(cb) {
                 users: body["users"],
                 bots: body["bots"],
                 self: body["self"],
-                channels: body["channels"]
+                channels: body["channels"],
+                groups: body["groups"]
             }, Date.now());
             _this.connectRtm(body.url);
         }