Install fails due to use of deprecated `sklearn` package

[benfogelson]

The requirements.txt file lists sklearn as a dependency. This is deprecated, and intermittently raises an error on install (see https://github.com/scikit-learn/sklearn-pypi-package).

I've made a PR to fix the issue: #133

[ceferisbarov]

A temporary fix:

1. Update requirements.txt yourself.
2. Run pip install -e . in the base folder.
3. Verify with pip show deberta