v0.9.0

1. Revise flaml.tune API

• Add a “scheduler” argument (a user can choose from “flaml”, “asha” or a customized scheduler)
• Rename "prune_attr" to "resource_attr"
• Rename “training_function” to “evaluation_function”
• Remove the “report_intermediate_result” argument (covered by “scheduler” instead)
• Add tests for the supported schedulers
• Re-run notebooks that use schedulers

2. Add save_best_config() to save best config in a json file

What's Changed

• add save_best_config() by @sonichi in #324
• tune api for schedulers by @qingyun-wu in #322
• add init.py in nlp by @sonichi in #325
• rename training_function by @qingyun-wu in #327

Full Changelog: v0.8.2...v0.9.0