Cmdkit

Minor fixes and improvements to the code. This also includes some refactoring that make it easier to patch behavior. Additions to CI/CD improve automation for the project.

This release includes a number of fixes and improvements. The notable feature addition is the ability to now add non-terminating options and flags to an `ApplicationGroup` interface and have them available in your applications. All groups along the hierarchy have their option namespaces merged and attached as `shared` to the Application class. So adding `my_opt` to a parent application group would be accessible from the downline application as `self.shared.my_opt`.

This release includes core fixes to the `Configuration` class and a new factory method for automatically loading configuration files and merging them. Also included is functionality to automatically explode and type-coerce a `Namespace` created from environment variables. Finally, an `ApplicationGroup` class makes it simple to create a hierarchical CLI without code duplication.

Application classes with resources can now define `__enter__` and `__exit__` methods. `Application.main` now initializes the application using a `with` statement.

After testing this in a few big projects it seems appropriate to bump to version 1.