add Timothy to tsc list

Refs: nodejs/TSC#520

PR-URL: nodejs/email#97
Refs: nodejs/TSC#520
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Ali Ijaz Sheikh <ofrobots@google.com>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>

iojs.org/aliases.json

@@ -16,7 +16,8 @@
     "rod@vagg.org",
     "rtrott@gmail.com",
     "targos@protonmail.com",
-    "thechargingvolcano@gmail.com"
+    "thechargingvolcano@gmail.com",
+    "timothygu99@gmail.com"
   ] },
   { "from": "ctc", "to": [
     "anna@addaleax.net",