Updates to prepare_data function (#29)

* update documentation links to point to the website

* Fix encoding

* Add rough time estimator based on historical stats

* Fix train_test split naming logic; add quiet mode for running inside scripts

* Add a finetuning step by step example for a classification use case.

* add classification params if train and valid set; add length_validator

Author: BorisPower

README.md

@@ -68,7 +68,7 @@ openai api completions.create -e ada -p "Hello world"
 
 ## Requirements
 
--   Python 3.6+
+-   Python 3.7+
 
 In general we want to support the versions of Python that our
 customers are using, so if you run into issues with any version