[TEST] mute failing tests, which are tracked in elastic/x-pack-elasticsearch#1511

Original commit: elastic/x-pack-elasticsearch@e23dd847f3

plugin/src/test/java/org/elasticsearch/xpack/security/authc/esnative/NativeRealmIntegTests.java

@@ -101,6 +101,7 @@ public class NativeRealmIntegTests extends NativeRealmIntegTestCase {
         }
     }
 
+    @AwaitsFix(bugUrl = "https://github.com/elastic/x-pack-elasticsearch/pull/1507")
     public void testDeletingNonexistingUserAndRole() throws Exception {
         SecurityClient c = securityClient();
         DeleteUserResponse resp = c.prepareDeleteUser("joe").get();

plugin/src/test/java/org/elasticsearch/xpack/security/authz/WriteActionsTests.java

@@ -54,6 +54,7 @@ public class WriteActionsTests extends SecurityIntegTestCase {
                 BulkAction.NAME + "[s]");
     }
 
+    @AwaitsFix(bugUrl = "https://github.com/elastic/x-pack-elasticsearch/issues/1511")
     public void testDelete() {
         createIndex("test1", "index1");
         client().prepareIndex("test1", "type", "id").setSource("field", "value").get();