Add license text to new files.

Author: fapifta

hadoop-common-project/hadoop-auth/src/main/java/org/apache/hadoop/security/authentication/util/ZookeeperClient.java

@@ -1,3 +1,17 @@
+/**
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License. See accompanying LICENSE file.
+ */
+
 package org.apache.hadoop.security.authentication.util;
 
 import org.apache.curator.RetryPolicy;

hadoop-common-project/hadoop-auth/src/test/java/org/apache/hadoop/security/authentication/util/TestZookeeperClientCreation.java

@@ -1,3 +1,17 @@
+/**
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License. See accompanying LICENSE file.
+ */
+
 package org.apache.hadoop.security.authentication.util;
 
 import org.apache.curator.RetryPolicy;