v0.4.1


- Ability to specify default printing in statsitical tests with the `suppress_print` keyword argument (default False).
- For the multivariate log rank test, the inverse step has been replaced with the generalized inverse. This seems to be what other packages use.
- Adding more robust cross validation scheme based on issue #67.
- fixing `regression_dataset` in `datasets`.
 

To avoid inconsistencies, perhaps make py2 and py3 work the same?

    from __future__ import division, print_function

and then use integer division :

    n // k + 1