ci: fix licensing

Signed-off-by: Alessandro Comodi <acomodi@antmicro.com>

.github/workflows/ci.yml

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a4b73b1..2daa4ea 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,3 +1,11 @@
+# Copyright (C) 2021  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
+
 name: CI
 
 on: [push, pull_request]

.github/workflows/licensing.yml

diff --git a/.github/workflows/licensing.yml b/.github/workflows/licensing.yml
index 3714cbc..bfe8a3d 100644
--- a/.github/workflows/licensing.yml
+++ b/.github/workflows/licensing.yml
@@ -21,4 +21,7 @@
     steps:
     - uses: actions/checkout@v2
 
-    - uses: SymbiFlow/actions/checks@main
\ No newline at end of file
+    - uses: SymbiFlow/actions/checks@main
+      with:
+        exclude_directory: |
+          - tests

.readthedocs.yml

diff --git a/.readthedocs.yml b/.readthedocs.yml
index 93b8e44..f0a333c 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -1,3 +1,11 @@
+# Copyright (C) 2021  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
+
 # .readthedocs.yml
 # Read the Docs configuration file
 # See https://docs.readthedocs.io/en/stable/config-file/v2.html for details

docs/environment.yml

diff --git a/docs/environment.yml b/docs/environment.yml
index 2cf62d9..d669a56 100644
--- a/docs/environment.yml
+++ b/docs/environment.yml
@@ -1,3 +1,11 @@
+# Copyright (C) 2021  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
+
 name: v2x-docs
 channels:
 - symbiflow