Invest % doesnt work in some cases

[Caribosaurus]

Describe the bug
In some cases the % ends up exceeding the actual balance, this probably due to python rounding when casting to ints

To Reproduce

1. have a balance of 7,847,709,332,162,940 M¢
2. !invest 100%
3. bot doesnt take it

Expected behavior
Invest all your money

TO FIX:
change
# Allows input such as '!invest 100%' and '!invest 50%' if suffix == '%': amount = int((investor.balance / 100) * int(amount))
to:
# Allows input such as '!invest 100%' and '!invest 50%' if suffix == '%': amount = int((investor.balance) * int(amount/100))
should also fix the error with one coin left after invest 100%