embark/dapps/tests/app/config/communication.json

{
  "default": {
    "client": "geth",
    "provider": "whisper",
    "enabled": true,
    "available_providers": ["whisper"],
    "connection": {
      "host": "localhost",
      "port": 3777,
      "type": "ws"
    }
  }
}