I agree that these are ultimately something that should be removed. The reason I did not is twofold:

1. It would necessitate a large number of changes in the interface for ```group_significance.py``` and I believe other scripts that use Pearson, Spearman, or Kendall. 

2. The p-value calculations that are made by these scripts in scipy (```scipy.stats.pearsonr, scipy.stats.spearmanr, scipy.stats.kendalltau```) are not necessarily the p-value calculations we want. I have not checked the ```scipy``` implementations vs. the implementations that we are currently using from Biometry, but I don't think they are the same. For instance, the ```scipy.stats.pearsonr``` documentation indicates that 
```The p-value roughly indicates the probability of an uncorrelated system
producing datasets that have a Pearson correlation at least as extreme
as the one computed from these datasets. The p-values are not entirely
reliable but are probably reasonable for datasets larger than 500 or so.```

Biometry suggests we can do far better than this with the Fisher Z transform. 

I am by no means committed to keeping the current implementation, I agree that it would be nice to get rid of these wrappers. I think it would be better to wait till post merge given the above two considerations (and perhaps after the initial release) but I will do whichever the group decides.