[BUG] Boolean arrays are not iterable

[v923z]

Taken from #588 (comment)

>>> b
array([False, True, False], dtype=bool)
>>> b[-1] = True
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'bool' object isn't iterable

@mtroback

[v923z]

Fixed in #613.