Update next version in matrix to 6.0.0 due to multiple major changes.

Author: cliffano

README.md

@@ -24,7 +24,7 @@ Version matrix
 
 | OpenAPI Ipify Version | OpenAPI Version | OpenAPI Generator Version |
 |-----------------------|-----------------|---------------------------|
-| 5.4.0 | 3.1.0 | 7.9.0 |
+| 6.0.0 | 3.1.0 | 7.17.0 |
 | 5.3.0 | 3.0.0 | 7.6.0 |
 | 5.2.0 | 3.0.0 | 7.4.0 |
 | 5.1.0 | 3.0.0 | 7.2.0 |