license: fix ISC license header from some scripts

Signed-off-by: Alessandro Comodi <acomodi@antmicro.com>
diff --git a/.github/test.sh b/.github/test.sh
index 24de367..caa6f60 100755
--- a/.github/test.sh
+++ b/.github/test.sh
@@ -1,4 +1,12 @@
 #!/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
 
 set -ex
 
diff --git a/v2x/__init__.py b/v2x/__init__.py
index 56fafa5..d01b7b8 100644
--- a/v2x/__init__.py
+++ b/v2x/__init__.py
@@ -1,2 +1,10 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
+#
+# 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
diff --git a/v2x/lib/__init__.py b/v2x/lib/__init__.py
index 56fafa5..d01b7b8 100644
--- a/v2x/lib/__init__.py
+++ b/v2x/lib/__init__.py
@@ -1,2 +1,10 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
+#
+# 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
diff --git a/v2x/xmlinc/__init__.py b/v2x/xmlinc/__init__.py
index 56fafa5..d01b7b8 100644
--- a/v2x/xmlinc/__init__.py
+++ b/v2x/xmlinc/__init__.py
@@ -1,2 +1,10 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
+#
+# 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
diff --git a/v2x/yosys/__init__.py b/v2x/yosys/__init__.py
index 56fafa5..d01b7b8 100644
--- a/v2x/yosys/__init__.py
+++ b/v2x/yosys/__init__.py
@@ -1,2 +1,10 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
+#
+# 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