The 1.5.x reference manual section Using Spock to test Spring Boot applications contains references to @SpringApplicationConfiguration and @WebIntegrationTest both of which were (to my knowledge) removed in 1.5.0.RELEASE.
The entire section is a bit weird, since it states that Spring Boot provides dependency management for Spock 1.0 while pointing users to use the removed classes if they don't override the managed version and use Spock 1.1.