improve update test to wait for green cluster state

Author: kimchy

src/test/java/org/elasticsearch/test/integration/update/UpdateTests.java

@@ -249,6 +249,9 @@ public void testUpdate() throws Exception {
                         .endObject())
                 .setRefresh(true)
                 .execute().actionGet();
+        clusterHealth = client.admin().cluster().prepareHealth().setWaitForGreenStatus().execute().actionGet();
+        assertThat(clusterHealth.timedOut(), equalTo(false));
+        assertThat(clusterHealth.status(), equalTo(ClusterHealthStatus.GREEN));
         updateResponse = client.prepareUpdate("test", "type1", "1").setScript("ctx._source.field += 1").setPercolate("*").execute().actionGet();
         assertThat(updateResponse.matches().size(), equalTo(1));