v2.0.0-alpha-3

What's Changed

• resolved some cases where the scheduler would be blocked when shutting down. Gotta be careful not be blocked when publishing or consuming from a channel. select is a good friend!
• added a bunch more tests and inline comments to help make it clear to anyone reading the code what's going on
• protected the standard job shutdown waitgroup with a mutex (hopefully that's the only mutex in the project)

Full Changelog: v2.0.0-alpha-2...v2.0.0-alpha-3