Tests (wrong screenshots and JRE version, delay) (#11255)

* wrong screenshots and JRE version

* delay for submenu

uitest/src/test/java/com/vaadin/tests/VerifyJreVersionTest.java

@@ -17,7 +17,7 @@ public class VerifyJreVersionTest extends SingleBrowserTest {
         WebElement jreVersionLabel = vaadinElementById("jreVersionLabel");
 
         assertThat(jreVersionLabel.getText(),
-                is("Using Java 1.6.0_45 by Sun Microsystems Inc."));
+                is("Using Java 1.8.0_181 by Oracle Corporation"));
     }
 
 }

uitest/src/test/java/com/vaadin/tests/components/menubar/MenuBarIconsTest.java

@@ -41,7 +41,7 @@ public class MenuBarIconsTest extends SingleBrowserTest {
     }
 
     @Test
-    public void imageIconsRendered() {
+    public void imageIconsRendered() throws Exception {
         openTestURL();
         MenuBarElement menu = $(MenuBarElement.class).id("image");
         WebElement moreItem = menu
@@ -58,7 +58,8 @@ public class MenuBarIconsTest extends SingleBrowserTest {
         assertImage(image, hasSubElement.findElement(By.vaadin("#Sub item")));
         // Close sub menu
         hasSubElement.click();
-
+        
+        sleep(500);
         assertImage(image, moreItem);
 
         moreItem.click();