Compile error for resolve_types from attrs

ImportError: cannot import name 'resolve_types' from 'attr' (/...../IdeaProjects/amazon-textract-a2i-pdf/venv/lib/python3.8/site-packages/attr/__init__.py)

Able to fix by updating to the latest version of attrs, 21.0.2

Pull request incoming.

Start by reproducing the resolve_types import error in the Python 3.8 environment and checking the installed attrs version. Done means resolve_types imports without ImportError after using attrs 21.0.2; the issue notes that a pull request is incoming.

Written by the indexing model from the issue text.