Add exchange Crypto.com

[liszper]

An uprising new exchange.

Exchange URL
https://crypto.com/exchange/

Exchange API URL
https://crypto.com/exchange-doc#ws-api

---

Refer to Contributing Guide for additional information.

[bmancini55]

Thanks, will take a look.

[bmancini55]

Additional dev notes:

• Should be able to extend BasicClient and issue individual subscription commands
• Request rate limits are 100 requests per second, recommend throttling messages sends to 20ms (refer to https://exchange-docs.crypto.com/#websocket)
• Will need to wire up heartbeats, exchange sends heartbeat every 30s and client must reply (refer to https://exchange-docs.crypto.com/#websocket-heartbeats)
• Supports tickers (refer to https://exchange-docs.crypto.com/#ticker-instrument_name)
• Supports trades (refer to https://exchange-docs.crypto.com/#trade-instrument_name)
• Supports candles (refer to https://exchange-docs.crypto.com/#candlestick-interval-instrument_name)
• Supports l2 order books, not sure if snapshot or update stream (refer to https://exchange-docs.crypto.com/#candlestick-interval-instrument_name)