The SELL side of the grid doesn't reach the maximum possible sell side orders

[kinbitz]

This check needs to be changed to allow the maximum number of levels for SELL side to reach the full size of the grid because it less than GRID_LEVELS, but to allow this change more code changes are needed.

https://github.com/PyWaves/BlackBot/blob/83838873d169563fd5f4ba06cbf1cf8000eb43a4/BlackBot.py#L37

This line has to be changed to grid = ["-"] * (GRID_LEVELS+1)

https://github.com/PyWaves/BlackBot/blob/83838873d169563fd5f4ba06cbf1cf8000eb43a4/BlackBot.py#L123

This line has to be changed to for n in range(last_level + 1, GRID_LEVELS+1):

https://github.com/PyWaves/BlackBot/blob/83838873d169563fd5f4ba06cbf1cf8000eb43a4/BlackBot.py#L166