Updated amsterdam.json for current organizers

Author: jpwesselink

chapters/amsterdam.json

@@ -3,8 +3,8 @@
   "location": "Amsterdam",
   "country": "NL",
   "region": "Europe",
-  "organizers": ["hughsk", "yoshuawuyts", "mmalecki", "hatchan"],
+  "organizers": ["jpwesselink", "rickheere", "stefanmirck", "codeflyer"],
   "website": "",
   "twitter": "",
   "repo": "http://github.com/nodeschool/amsterdam"
-}
+}