Update Objectify version in test (#3598)

Author: chanseokoh

plugins/com.google.cloud.tools.eclipse.appengine.libraries.test/src/com/google/cloud/tools/eclipse/appengine/libraries/model/CloudLibrariesInPluginXmlTest.java

@@ -168,7 +168,7 @@ public void testObjectifyLibraryConfig() throws URISyntaxException {
     assertThat(objectifyMavenCoordinates.getArtifactId(), is("objectify"));
     DefaultArtifactVersion artifactVersion = new DefaultArtifactVersion(
         objectifyMavenCoordinates.getVersion());
-    assertEquals(new DefaultArtifactVersion("6.0.5"), artifactVersion);
+    assertEquals(new DefaultArtifactVersion("6.0.6"), artifactVersion);
     assertThat(objectifyMavenCoordinates.getType(), is("jar"));
     assertNull(objectifyMavenCoordinates.getClassifier());