read_hippocampal_volume_file_dataframe test: ignore order of rows & columns to fix tests failing with python3.5
E AssertionError: DataFrame.columns are different
E
E DataFrame.columns values are different (100.0 %)
E [left]: Index(['T1_input', 'analysis_id', 'hemisphere', 'subfield', 'subject',
E 'volume_mm^3'],
E dtype='object')
E [right]: Index(['subfield', 'volume_mm^3', 'T1_input', 'hemisphere', 'analysis_id',
E 'subject'],
E dtype='object')
https://travis-ci.org/fphammerle/freesurfer-volume-reader/jobs/525359312#L290