add NOTICE file
diff --git a/NOTICE.txt b/NOTICE.txt
new file mode 100644
index 0000000..c575a46
--- /dev/null
+++ b/NOTICE.txt
@@ -0,0 +1,5 @@
+Apache Horn (incubating)
+Copyright 2015 The Apache Software Foundation
+
+This product includes software developed at
+The Apache Software Foundation (http://www.apache.org/).