Migrate Couchbase tests to JUnit 5.

Closes #664

couchbase/transactions/src/main/java/com/example/demo/DemoApplication.java

@@ -17,28 +17,15 @@ package com.example.demo;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
-import org.springframework.context.annotation.Condition;
-import org.springframework.context.annotation.ConditionContext;
-import org.springframework.context.annotation.Conditional;
-import org.springframework.core.type.AnnotatedTypeMetadata;
-
-import example.springdata.couchbase.util.CouchbaseAvailableRule;
 
 /**
  * @author Michael Reiche
  */
 @SpringBootApplication
-@Conditional(DemoApplication.CouchbaseAvailable.class)
 public class DemoApplication {
 
     public static void main(String[] args) {
         SpringApplication.run(DemoApplication.class, args);
     }
 
-    static class CouchbaseAvailable implements Condition {
-        @Override
-        public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
-            return CouchbaseAvailableRule.onLocalhost().isAvailable();
-        }
-    }
 }

couchbase/transactions/src/test/java/com/example/demo/DemoApplicationTests.java

@@ -15,25 +15,20 @@
  */
 package com.example.demo;
 
-import org.junit.ClassRule;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.test.context.SpringBootTest;
-import org.springframework.test.context.ContextConfiguration;
 
-import example.springdata.couchbase.util.CouchbaseAvailableRule;
+import example.springdata.couchbase.util.EnabledOnCouchbaseAvailable;
 
 /**
  * @author Michael Reiche
  * @author Christoph Strobl
  */
-@SpringBootTest
-@ContextConfiguration(classes = DemoApplication.class)
+@SpringBootTest(classes = DemoApplication.class)
+@EnabledOnCouchbaseAvailable
 class DemoApplicationTests {
 
-    @ClassRule //
-    public static CouchbaseAvailableRule COUCHBASE = CouchbaseAvailableRule.onLocalhost();
-
     @Test
     void contextLoads() {
     }