hypothesis-numpy 0.6.0

This adds support for numpy types to Hypothesis.

This should be considered more of a prototype than a serious piece of production software. Usage is as follows:

>>> from hypothesis import find
>>> from hypothesis.extra.numpy import arrays
>>> find(arrays(float, 2), lambda x: x.sum() >= 1)
array([ 1.,  0.])
>>> find(arrays(bool, (2, 2)), lambda x: x.any())
array([[False, False],
       [ True, False]], dtype=bool)
>>> find(arrays('uint64', (2, 2)), lambda x: x.any())
array([[1, 0],
       [0, 0]], dtype=uint64)