0.6.0 alpha

This update adds the following features:

• Make Certomancer Animator easier to remount in WSGI (through SCRIPT_NAME). For convenience, an optional argument to animate was added as well.
• Added CLI arguments to override the external URL prefix specified in the configuration.
• Support including pregenerated certificates in the configuration
• Support key set templates
• Support reusing entire PKI architectures as templates for other ones.

The following miscellaneous were applied:

• Update pyhanko-certvalidator dependency in tests.
• Added some asynchronous tests (with pytest-aiohttp for compatibility with the pyhanko-certvalidator test suite, though any asyncio plugin for pytest should work)