Skflex

- Update docs

- Fixed bug with y axis label for validation plot

- added further explanation for classifier_train_report summary

- Fixed bug with scoring parameter for classifier_train_report. The function now accepts the strings 'accuracy', 'f1', 'recall' and 'precision' as arguments for scoring.

- added a 'scale_data' parameter for the pca_scree_plot function that will normalise data passed in before performing analysis and plotting.

- Update docs and provide examples

- First release.