wip/py-test-mpl 0.17.0 NetBSD

This is a plugin to facilitate image comparison for Matplotlib figures in pytest. Matplotlib includes a number of test utilities and decorators, but these are geared towards the nose testing framework. Pytest-mpl makes it easy to compare figures produced by tests to reference images when using pytest.

For each figure to test, the reference image is subtracted from the generated image, and the RMS of the residual is compared to a user-specified tolerance. If the residual is too large, the test will fail (this is implemented using helper functions from matplotlib.testing).