Merge branch 'predict_gain' into newmain-gain

MANIFEST.in

data/coef_mean_model.tsv

data/combi_sample.tsv

data/combination_example.tsv

data/gain_results.tsv

data/range_feature_gain_prediction.tsv

doc/source/get_predicted_gain.rst

doc/source/index.rst

doc/source/reference.bib

jass/__main__.py

jass/models/data/coef_mean_model.tsv

jass/models/data/range_feature_gain_prediction.tsv

jass/models/gain.py

setup.py