Approximate rate

{
 "action": "subscribe-public",
 "module": "cantor_service",
 "path": "rates/{source_currency}/{destination_currrency}"
}

{
  "action": "push",
  "topic": "cantor_service/rates/usd/eur",
  "message": {
    "rate": 1.164875,
    "rateCurrency": "USD"
  },
  "timestamp": "1576845911374",
  "seqNo": 4317604
}