AttributeError: 'ReentrantFileLock' object has no attribute '_lock'

when running `make tests` I get the error: `AttributeError: 'ReentrantFileLock' object has no attribute '_lock'` on the master branch

going through the steps in https://docs.kinto-storage.org/en/latest/community.html#get-started

Start with the get-started steps in the linked community documentation and run `make tests` to capture the full traceback. Trace where `ReentrantFileLock` is defined and where its `_lock` attribute is accessed. Done means the reported AttributeError is resolved and the test command completes successfully.

Written by the indexing model from the issue text.