check_python_script: Add missing license header.

Signed-off-by: Tim 'mithro' Ansell <me@mith.ro>

.github/travis/check_python_script.sh

diff --git a/.github/travis/check_python_script.sh b/.github/travis/check_python_script.sh
index d34c586..4695a84 100644
--- a/.github/travis/check_python_script.sh
+++ b/.github/travis/check_python_script.sh
@@ -1,5 +1,13 @@
 #!/bin/bash
 
+# Copyright (C) 2020  The SymbiFlow Authors.
+#
+# Use of this source code is governed by a ISC-style
+# license that can be found in the LICENSE file or at
+# https://opensource.org/licenses/ISC
+#
+# SPDX-License-Identifier:	ISC
+
 echo
 echo "==================================="
 echo "Check python utf coding and shebang"