Merge branch 'release/0.9.16' into develop
Removing 'use_dense_features' and 'do_scale_features' options from the
config file and use a single 'feature_scaling' option that will
automatically convert features to dense if required.
Fixed link formatting issue in README
Added a unit test for feature scaling
Removed 'scale_features' from experiments.py defaults.
Fixed bug in test_skll.py that made it fail with python 3.
Merge pull request #42 from EducationalTestingService/feature/remove_use_dense_features_option

Remove 'use_dense_features' option.
refactored data.py to facilitate using Learner.predict() programmatically
added keywords for some kwargs
added an optional ids_to_floats config option (defaulting to False).  added unit tests
added note about ids_to_floats in documentation
changed assert to eq_ in some tests
Merge pull request #45 from EducationalTestingService/feature/convert_data_for_predict

Don't convert IDs to float by default anymore, and added ids_to_floats option to config file.
Also added a utility function for converting a list of dictionaries to an ExamplesTuple directly.
Update changelog and bumped version to 0.9.17.
Merge branch 'release/0.9.17'