ComputationalCryoEM/ASPIRE-Python: v0.9.1

ASPIRE v0.9.1 is a patch release. This release adds the following new features: crop_pad_2d() in aspire.utils.coor_trans Bug fixes: Some images appeared flipped by 180 degrees in Reddy Chatterji image registration. Basis objects did not stop the user from expanding images that did not match the size of the basis. ArrayImageSource should have integer filter indices. Code cleanup: Basis objects can be instantiated with an integer instead of a tuple when creating square or cubic bases. More descriptive commenting and docstrings added to Bessel function zero-finding code. Testing for Downsampling and Fourier-Bessel 2D basis that used to depend on hardcoded results and output files now instead test expected mathematical properties. Improvements to the gallery section of the documentation page include grammar fixes, updates to the author page, and a consistent color map for all images in experiment demonstrations