Bug Fixes in echo-opt and echo-report

[sophiaanr]

Fixed bugs related to old versions of scikit-learn and xgboost for partial dependence plots.
In echo-report, I changed the trial_report to return the state names instead of the numeric id.
I also changed echo-opt to accept absolute or relative paths when calling echo-opt hyper_config model_config rather than in the directory where configs are located.