Allow for unicode chars in ios notifications

[AdriVanHoudt]

Currently I am getting these errors:

2015/11/26 16:41:26 Alert (iOS): {"aps":{"alert":"Test: 💬test","badge":-1,"sound":"bingbong.aiff"},"payload":{"event":"notification","data":{"message_text":"Test: 💬 test","notification":{"body":"💬 test","id":121,"image":"urlToImage","tag":121,"title":"Test"}},"time":1448556086}}
2015/11/26 16:41:26 Error (iOS): encoding/hex: invalid byte: U+0074 't'

I add them in javascript like this: '\uD83D\uDCAC'
EDIT: adding like 💬 in js does not help