Fix license in health handler py (#3376)

diff --git a/LICENSE b/LICENSE
index 360aa7f..0498e42 100644
--- a/LICENSE
+++ b/LICENSE
@@ -248,8 +248,6 @@
       -> scripts/packages/tests_template_bin.sh
       -> scripts/packages/bin_common.sh
       -> third_party/java/bazel/extra_actions_base.proto
-    Twitter
-      -> heron/shell/src/python/handlers/healthhandler.py
     Google
       -> third_party/java/jarjar/src/main/resources/com/tonicsystems/jarjar/help.txt
 
diff --git a/heron/shell/src/python/handlers/healthhandler.py b/heron/shell/src/python/handlers/healthhandler.py
index 26bd667..2455ad5 100644
--- a/heron/shell/src/python/handlers/healthhandler.py
+++ b/heron/shell/src/python/handlers/healthhandler.py
@@ -1,19 +1,22 @@
 #!/usr/bin/env python
 # -*- encoding: utf-8 -*-
 
-# Copyright 2016 Twitter. All rights reserved.
-#
-# 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
+#  Licensed to the Apache Software Foundation (ASF) under one
+#  or more contributor license agreements.  See the NOTICE file
+#  distributed with this work for additional information
+#  regarding copyright ownership.  The ASF licenses this file
+#  to you 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.
+#  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.
 
 """ healthhandler.py """
 import tornado.web