text: Title: Can you add additional liquidation feed?
  Body: Looking at standards.py, it looks like Bitmex is the only liquidation feed?
  
  ```
      LIQUIDATIONS: {
          BITMEX: 'liquidation'
      }
  ```
  
  There is another project that I've been watching (that is also pretty awesome IMHO), [SignificantTrades](https://github.com/Tucsky/SignificantTrades)..  I'm particularly interested in Binance (in this case Binance Futures) at this time, because that is where I have funds.  So...I guess that is why I am aware of this.
  
  The project here:
  > line 82 of:
  > https://github.com/Tucsky/SignificantTrades/blob/master/src/exchanges/binance-futures.js
  
  The stream is 'forceOrder'.  Documentation here:
  
  > https://binance-docs.github.io/apidocs/futures/en/#liquidation-order-streams
  
  Looking at the docs, it looks like they also have a feed for all liquidations regardless of the pair.  I kind of would be curious to collect and look at this and see what is going on..  Don't know if it would 'fit in' w/how things are setup now though?