fix(aws/integration): fix scope of setup method while upgrading junit…

… to 5.9.0

to fix:

> Task :clouddriver-aws:integrationTest

  com.netflix.spinnaker.clouddriver.aws.test.CreateServerGroupSpec ✘ initializationError

    org.junit.platform.commons.JUnitException: @beforeeach method 'private void com.netflix.spinnaker.clouddriver.aws.test.CreateServerGroupSpec.init(org.junit.jupiter.api.TestInfo)' must not be private.

clouddriver-aws/src/integration/java/com/netflix/spinnaker/clouddriver/aws/test/CreateServerGroupSpec.java

@@ -89,7 +89,7 @@ public class CreateServerGroupSpec extends AwsBaseSpec {
   private AmazonEC2 mockEc2 = mock(AmazonEC2.class);
 
   @BeforeEach
-  private void init(TestInfo testInfo) {
+  void init(TestInfo testInfo) {
     System.out.println("--------------- Test " + testInfo.getDisplayName());
 
     // mock EC2 responses