NF: Add compare_cdfs_from_dataframe(), calculate_t_tests()
NF: Hopefully get Travis-CI working with scipy
NF/RF: calculate_t_tests() is now calculate_statistics()
NF/BF: Add calculate_statistics()
BF: Typo
DOC: Add documentation
RF: We do not yet have a test for statistics
Merge remote-tracking branch 'origin/devel' into calculate-from-raw-dataframe
DOC: Update docstring