Feature/feature file ordering

Resolves #149.  Maybe.  Since this is based off the unit test branch by @desilinguist, which might not work, this might not work yet.
Please use `assert_array_equal` instead of `assert np.all...` throughout.

Really, whenever possible do not actually use a plain `assert` for testing, because that will not actually print out the values that caused the assertion to fail.  There are testing helper methods that print more useful messages in `nose.tools`, `numpy.test`, and `sklearn.utils.testing`.