Proper stop losses coming soon

[askmike]

There is also some code that looks like it might help with adding stop loss to any order located here:
https://github.com/askmike/gekko/pull/1317/files

That code hooks into very old Gekko code, unfortunately we have to start from scratch implementing them in Gekko Broker instead.

I have modified a simple strategy that uses an EMA cross to identify an exit which seems to function similarly to a trailing stop loss.

Having stop losses at the strategy level is great, but it's not perfect for a few reasons: the biggest one being that the strategy can only check once every X minutes whether it should trigger a stop (X being the configured candle size). Besides that if we use Gekko Broker we can also use native stop losses for exchanges that support them (like on binance).