FIX: Raise value error if window data-type is unsupported

[venthur]

Added unittest. (I had to derive the Test class from unittest.TestCase to use
self.asserRaises. This had no effect on the other tests of this class as they
use numpys test assertions. The number of executed tests was unchanged.
Fixes #3603

[ev-br]

you can use

>>> from numpy.testing import assert_raises
>>> def f(x): return 1./x
>>> assert_raises(ZeroDivisionError, f, 0)
>>> >>> assert_raises(ZeroDivisionError, f, 1)
Traceback (most recent call last):
<snip>
AssertionError: ZeroDivisionError not raised

[venthur]

Cool, thanks! (and fixed)

[coveralls]

Changes Unknown when pulling a7c2677 on venthur:fix-3603 into * on scipy:master*.

[coveralls]

Changes Unknown when pulling a7c2677 on venthur:fix-3603 into * on scipy:master*.

[pv]

LGTM.

Doesn't fully fix gh-3603, however, as that requires changing:

 elif isinstance(window, ndarray) and window.shape == (Nx,):
      W = window

in signaltools.py:resample to something more sensible (move shape check inside if statement and raise an error if it fails).