Merge branch 'release/0.15.0' into develop
Fix incorrect link in documentatino
Update parameter grid documentation
Revamped handling of logging and added warning about skipping IDs.
No longer set compute_importances since it is unnecessary (and triggers a deprecation warning) with sklearn 0.14+.
Clean up API documentation a bit.
Add versions of quadratic, linear, and unweighted kappa that treat ratings that are off by one as equivalent.
Clean up grid search code a little bit and fix outdated comments.
Removed unnecessary n_estimators bit from paramater grid for GradientBoosting models, since that's already set in Learner.__init__
Switch to float for converting IDs.
Add duplicate feature name check to _megam_dict_iter.
Fix check for duplicate feature names in MegaM files.
Bumped version to 0.16.0 and updated changelog.
Merge branch 'release/0.16.0'