Fix poloniex minimal cost
Fix poloniex minimal cost

It is currently possible to receive this exception from poloniex:

```
ccxt.base.errors.InvalidOrder: poloniex {"error":"Total must be at least 0.0001."}
```

Inspired by https://github.com/askmike/gekko/pull/2167/, and specifically https://github.com/askmike/gekko/pull/2167/files#diff-c212a282e676846ba239680f7a180455R255, I copied the known minimums based on the market quote currency.
ccxt/ccxt,ccxt/ccxt,ccxt/ccxt,ccxt/ccxt,ccxt/ccxt