v0.1.0 - Functional for orthogonal grids

This version should be able to run elementary tests on maps using test_pdf_map_where, test_pdf_map_wheregex and test_pdf_map_single_case unless they have angles different than 90 degrees. Currently it reports kurtosis and variance, but these should not be trusted as the size of grid matters. In future releases grid trimming and non-right angles will be included.