[chore] Bump engine.io-client to version 2.0.2 (socketio#1074)

Includes the following (from engine.io-client changelog):

* [chore] Bump ws to version 1.1.2 (vulnerability fix) ([socketio#539](socketio/engine.io-client#539))
* [fix] Fix extraHeaders option in browser ([socketio#536](socketio/engine.io-client#536))

package.json

@@ -19,7 +19,7 @@
     "component-bind": "1.0.0",
     "component-emitter": "1.2.1",
     "debug": "2.3.3",
-    "engine.io-client": "2.0.0",
+    "engine.io-client": "2.0.2",
     "has-binary": "0.1.7",
     "indexof": "0.0.1",
     "object-component": "0.0.3",