Move to junit5 in all framework tests

- Just a migration
- Replace RedisRule with EnabledOnRedis
- Replace MongoDbRule with EnabledOnMongoDb
- spring-statemachine-test and some docs contains refs to junit4
  but those are support packages and will stay in place.
- Fixes #779
- Relates #771

spring-statemachine-samples/turnstilereactive/src/test/java/demo/turnstilereactive/TurnstileReactiveTests.java

@@ -17,20 +17,20 @@ package demo.turnstilereactive;
 
 import static org.hamcrest.CoreMatchers.containsString;
 
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
 import org.springframework.http.MediaType;
 import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.annotation.DirtiesContext.ClassMode;
-import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
 import org.springframework.test.web.reactive.server.WebTestClient;
 
 import reactor.core.publisher.Mono;
 
-@RunWith(SpringRunner.class)
+@ExtendWith(SpringExtension.class)
 @SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
 @DirtiesContext(classMode = ClassMode.AFTER_EACH_TEST_METHOD)
 public class TurnstileReactiveTests {