Add NOTICE.txt

NOTICE.txt

@@ -0,0 +1,24 @@
+Hyperspace
+Copyright (2020) The Hyperspace Project Authors.
+
+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.
+
+This project includes software licensed by the Apache Software Foundation (Apache 2.0)
+from the Apache Spark project (www.github.com/apache/spark)
+
+----------------------------------------------------------
+Apache Spark
+Copyright 2014 and onwards The Apache Software Foundation.
+
+This product includes software developed at
+The Apache Software Foundation (http://www.apache.org/).