Version 0.12.3

FIX #1061: Fixes a bug where the model could not be printed in a jupyter notebook.
FIX #1075: Fixes a bug where the ensemble builder would wrongly prune good models for loss functions (i.e. functions that need to be minimized such as logloss or mean_squared_error.
FIX #1079: Fixes a bug where AutoMLClassifier.cv_results and AutoMLRegressor.cv_results could rank results in opposite order for loss functions (i.e. functions that need to be minimized such as logloss or mean_squared_error.
FIX: Fixes a bug in offline meta-data generation that could lead to a deadlock.
MAINT #1076: Uses the correct multiprocessing context for computing meta-features
MAINT: Cleanup readme and main directory

Contributors v0.12.3