Addextras andattr properties to theExtension class tomake it easier for consumers to access the underlying properties,regardless of the version ofimportlib.metadata being used.

Add amodule_name property to theExtension class to make it easierfor consumers to determine where the plugin is being loaded from.

Adds a caching layer. The cache is a single JSON file createdautomatically in the user’s home directory. It stores the parsedtext data from all of the metadata input files in a file with aname based on the hash of the contents andsys.path, ensuringuniqueness for applications installed into different virtualenvironments.

The type of the entry point objects returned has changed frompkg_resources.EntryPoint toimportlib.metadata.EntryPoint. Thenew objects still have aload() method, but some of the otherAPIs are different.

Support for Python 2.7 is removed. Python 3.6 or greater is now required.

Introduce reno for deployer release notes.