boto3 breaks if pytest-localstack tests run before moto

[charlieparkes]

Using both pytest-localstack and moto in the same project may break if the pytest-localstack tests run first. It's suspected this is due to an issue with cleanup with the pytest-localstack session.

https://github.com/mintel/pytest-localstack/blob/master/pytest_localstack/contrib/botocore.py#L406