• Fix compatibility issue with scikit-learn v0.22
• warm_start now saves both Primitive Sets and evaluated_pipelines_ from previous runs;
• Fix the error that TPOT assign wrong fitness scores to non-evaluated pipelines (interrupted by max_min_mins or KeyboardInterrupt) ;
• Fix the bug that mutation operator cannot generate new pipeline when template is not default value and warm_start is True;
• Fix the bug that max_time_mins cannot stop optimization process when search space is limited.
• Fix a bug in exported codes when the exported pipeline is only 1 estimator
• Fix spelling mistakes in documentations
• Fix some code quality issues