Beta 0.2.4

• Fix - Special case when running data with no missing data and imputation was 'True', apply model error when looking for non existent imputation file. Code fixed so that importing imputed file is in try/except loop to prevent fail. Also updated apply model so that both .csv and .txt replication data can be loaded.
• At recommendation of collaborator, switched from mean to median scores for feature importance figures. Also now outputs median algorithm performance summary, and adds median performance to pdf summary. Also now present median values in statistical significance output since this pairs more appropriately with non-parametric statistics than mean and standard deviation.