reactive/webflux/hello-security useJUnitPlatform

reactive/webflux/hello-security/build.gradle

@@ -18,3 +18,7 @@ dependencies {
 	testImplementation 'org.springframework.boot:spring-boot-starter-test'
 	testImplementation 'org.springframework.security:spring-security-test'
 }
+
+tasks.withType(Test).configureEach {
+	useJUnitPlatform()
+}