test: replace mock with builder (3414)

Replaced Mockito.mock by creating actual object
---
 remove redundant initialization of javaProject in setup method
---
Removed Unused Imports

jkube-kit/jkube-kit-openliberty/src/test/java/org/eclipse/jkube/openliberty/OpenLibertyUtilsTest.java

@@ -24,9 +24,7 @@
 import java.nio.file.Files;
 
 import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
-import static org.mockito.Answers.RETURNS_DEEP_STUBS;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
+
 
 class OpenLibertyUtilsTest {
 
@@ -36,8 +34,9 @@ class OpenLibertyUtilsTest {
 
   @BeforeEach
   void setup() {
-    javaProject = mock(JavaProject.class, RETURNS_DEEP_STUBS);
-    when(javaProject.getBaseDirectory()).thenReturn(temporaryFolder);
+    javaProject = JavaProject.builder()
+            .baseDirectory(temporaryFolder)
+            .build();
   }
 
   @Test