v0.3.0

What's Changed

• rich error returns always class and a message by @simonneutert in #6
• Bump rubocop from 1.52.1 to 1.53.0 by @dependabot in #7
• bump rubocop by @simonneutert in #8
• locking in between bookings can cause saldo to become negative (edge case / theoretical) by @simonneutert in #10

Full Changelog: v0.2.1...v0.3.0