catboost 0.10.3 on Python PyPI

Changes:

Added EvalResult output after GPU catboost training
Supported prediction type option on GPU
Added get_evals_result() method and evals_result_ property to model in python wrapper to allow user access metric values
Supported string labels for GPU training in cmdline mode
Many improvements in JNI wrapper
Updated NDCG metric: speeded up and added NDCG with exponentiation in numerator as a new NDCG mode
CatBoost doesn't drop unused features from model after training
Write training finish time and catboost build info to model metadata
Fix automatic pairs generation for GPU PairLogitPairwise target