Servlet 4.0 is finally GA now, with its API available in final form from Maven Central. Let's upgrade spring-test to it for actual MockServletContext overrides, and also spring-webmvc for non-reflective PushBuilder injection with corresponding tests (
spring-web keeps building against the Servlet API 3.1 for the time being. This may change as we start to optionally integrate with specific Servlet 4.0 features in the core web facilities (e.g. SPR-15320 in UrlPathHelper outside of spring-webmvc) but isn't necessary at this point.