Errors in tests

[mcartwright]

While adding tests for #40, I noticed what seem to be a couple of errors in the test_deformers.py.

In test_linear_pitchshift, shouldn't assert lower <= d_tones <= 2.0**upper be assert lower <= d_tones <= upper?

also, in __test_effect, I think you intend for there to be an assert there, correct? i.e. ann_orig == ann_new -> assert ann_orig == ann_new

[bmcfee]

Thanks for catching that!