Gaffer 1.15.0

✨ New Features

• Classifier should be added to spring-rest api #2391
• Proxy Store should be able to target non /v2 endpoints #2388
• Allow spring-rest to be used by multiple stores with standard libraries #2387
• Add action to rerun the last release #2380
• Implement the visibility trait for the MapStore #801

🪲 Bugs Fixed

• Proxy Store should be able to send operations to the spring-rest #2390
• Spring rest api doesn't return helpful error messages when JSON is invalid #2389
• Spring rest only returns results if Accept: application/json is set #2386