Tibber-aws

* Add delete file function to S3Bucket class

* Package requirements bugfix. Will install async-exit-stack on python versions before 3.7 because it was added to standard library in 3.7

What's Changed
* Add get_aiosession by Danielhiversen in https://github.com/tibbercom/tibber-pyAws/pull/28


**Full Changelog**: https://github.com/tibbercom/tibber-pyAws/compare/0.9.0...0.9.1

What's Changed
* 3.10-dev by Danielhiversen in https://github.com/tibbercom/tibber-pyAws/pull/25
* 3.10 by Danielhiversen in https://github.com/tibbercom/tibber-pyAws/pull/26
* Make init_client_if_required public and add a lock by Danielhiversen in https://github.com/tibbercom/tibber-pyAws/pull/27


**Full Changelog**: https://github.com/tibbercom/tibber-pyAws/compare/0.8.6...0.9.0