TestLearners AUC metric.
Clean imports.
Improve code clarity.
Binary measures.
Merge pull request #182 from acopar/test-learners-auc

Test learners auc
Supported numpy arrays as inputs for distances. Handling e1, e2 separately. Implemented extension ob basic classes.
Added documentation for Distances.
Merge pull request #181 from nikicc/npmat

Supported numpy arrays as inputs for distances.