Improve support for Python 3.12, drop Python 3.6 support

drop pyinotify in favour of inotify_simple

0.25: Merge pull request #40 from planetlabs/atomic-enqueue

Enqueue files atomically for upload

0.24: Merge pull request #39 from planetlabs/latest

expose latest file functionality in client

0.23: Merge pull request #38 from gleeco/check-aws-default-region

fix: check for aws default region