Fast randomization based two sample tests. Testing the hypothesis that two samples come from the same distribution using randomization to create p-values. Included tests are: Kolmogorov-Smirnov, Kuiper, Cramer-von Mises, and Anderson-Darling. There is also a very efficient test based on the Wasserstein Distance. The default test 'two_sample' builds on the Wasserstein distance by using a weighting scheme like that of Anderson-Darling. We also include the permutation scheme to make test building simple for others.