yarn 0.1.0

Yarn is a simple task runner that uses PostgreSQL as storage. Yarn has the following goals:

• Simple and predictable: Scheduling and running tasks should be easy to reason about and use.
• Exclusively target PostgreSQL as storage: Adding other backends raises complexity substantially.
• Transactional guarantees: Using PostgreSQL, you can register tasks in your database transactions (currently only sqlx supported).
• Scheduled and regular tasks: Submit tasks to run now, later or at regular intervals (similar to cron).