Fixes CalculateOrderQuantity to handle decimal quantities
Fixes CalculateOrderQuantity to handle decimal quantities

In quantity calculation, we didn't reduce the order quantity by decimal numbers, leading to a big step when dealing with crypto-currencies. For example, from 2.3456 it would drop to 1.3456 where values in between should've been tested.

kaffeebrauer/Lean,AlexCatarino/Lean,StefanoRaggi/Lean,jameschch/Lean,StefanoRaggi/Lean,AnshulYADAV007/Lean,Jay-Jay-D/LeanSTP,kaffeebrauer/Lean,AnshulYADAV007/Lean,QuantConnect/Lean,QuantConnect/Lean,AnshulYADAV007/Lean,AlexCatarino/Lean,redmeros/Lean,Jay-Jay-D/LeanSTP,Jay-Jay-D/LeanSTP,AlexCatarino/Lean,AlexCatarino/Lean,Jay-Jay-D/LeanSTP,kaffeebrauer/Lean,AnshulYADAV007/Lean,StefanoRaggi/Lean,kaffeebrauer/Lean,JKarathiya/Lean,jameschch/Lean,jameschch/Lean,QuantConnect/Lean,QuantConnect/Lean,JKarathiya/Lean,kaffeebrauer/Lean,JKarathiya/Lean,redmeros/Lean,redmeros/Lean,JKarathiya/Lean,AnshulYADAV007/Lean,StefanoRaggi/Lean,Jay-Jay-D/LeanSTP,StefanoRaggi/Lean,redmeros/Lean,jameschch/Lean,jameschch/Lean