Release 5.4.0

Changed

• Client version updated on 5.4.3, by @HardNorth
• Replace "jsr305" annotations with "jakarta.annotation-api", by @HardNorth
• Switch on use of Instant class instead of Date to get more timestamp precision, by @HardNorth

Fixed

• Issue #53: NPE on specs with setup methods, by @HardNorth

Removed

• Java 8-10 support, by @HardNorth