Permutation test: wild type versus heterozygote

Test the hypothesis that the heterozygote and wild type bout lengths are identically distributed using a permutation test.

Compute the difference of means (heterozygote minus wild type bout lengths) of the actual data sets, storing the result in the variable diff_means_exp. The numpy arrays bout_lengths_wt and bout_lengths_het are already in your namespace.
Draw 10,000 permutation replicates of the difference of means using dcst.draw_perm_reps(). You can use the dcst.diff_of_means() function as well, storing your result in perm_reps.
Compute the p-value, defining "at least as extreme as" to be that the difference of means under the null hypothesis is greater than or equal to that which was observed experimentally.
Print the p-value to the screen.