Aws-error-utils

* Remove support for Python 3.6.

* Add `errors.ALL` to match all `ClientError`s.

* Fix type annotations.

* Require Python 3.6 as 3.5 is EOL.
* Update `AWSErrorInfo` to be a dataclass.
* Add type annotations ([4](https://github.com/benkehoe/aws-error-utils/issues/4)).
* Required refactoring from plain single-file module into package for `py.typed` file; single-file module within the package is [here](https://raw.githubusercontent.com/benkehoe/aws-error-utils/stable/aws_error_utils/aws_error_utils.py).

* Add `make_aws_error()` function for testing ([5](https://github.com/benkehoe/aws-error-utils/issues/5)).

* Add `errors` class for simpler syntax (README.mderrors).