Move back to JUnit 4 until SUREFIRE-1614 has been resolved

See gh-14736
See gh-14737
See gh-14738

spring-boot-samples/spring-boot-sample-data-rest/src/test/java/sample/data/rest/SampleDataRestApplicationTests.java

@@ -16,11 +16,13 @@
 
 package sample.data.rest;
 
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
 import org.springframework.test.web.servlet.MockMvc;
 import org.springframework.test.web.servlet.setup.MockMvcBuilders;
 import org.springframework.web.context.WebApplicationContext;
@@ -39,7 +41,7 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
  * @author Oliver Gierke
  * @author Andy Wilkinson
  */
-
+@RunWith(SpringRunner.class)
 @SpringBootTest
 // Separate profile for web tests to avoid clashing databases
 public class SampleDataRestApplicationTests {
@@ -49,7 +51,7 @@ public class SampleDataRestApplicationTests {
 
 	private MockMvc mvc;
 
-	@BeforeEach
+	@Before
 	public void setUp() {
 		this.mvc = MockMvcBuilders.webAppContextSetup(this.context).build();
 	}

spring-boot-samples/spring-boot-sample-data-rest/src/test/java/sample/data/rest/service/CityRepositoryIntegrationTests.java

@@ -16,13 +16,15 @@
 
 package sample.data.rest.service;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
+import org.junit.runner.RunWith;
 import sample.data.rest.domain.City;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
+import org.springframework.test.context.junit4.SpringRunner;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -32,7 +34,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  * @author Oliver Gierke
  * @author Andy Wilkinson
  */
-
+@RunWith(SpringRunner.class)
 @SpringBootTest
 public class CityRepositoryIntegrationTests {