__truediv__ is broken for num / bm

[timlnx]

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ERROR: truediv: number / bitmath = number
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Traceback (most recent call last):
  File "/home/tbielawa/Projects/bitmath/tests/test_future_math.py", line 61, in test_number_div_bitmath_is_number
    result = num1 / bm1
TypeError: unsupported operand type(s) for /: 'int' and 'KiB'

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Ran 3 tests in 0.001s

FAILED (errors=1)

However, bm / bm and bm / num work properly.