chore: add spdx license identifier header to test modules

[afuetterer]

This PR adds a spdx license identifier header to the test modules I created prior. This adds the license information, without being as verbose as the other modules.

What do you think?

Ref: https://spdx.dev/learn/handling-license-info/

[coveralls]

coverage: 67.553%. remained the same — afuetterer:license into chrismattmann:master

[afuetterer]

Would you like to replace the verbose license header in the other modules with this one-liner as well?

I am unsure if you really need this boilerplate. There is no NOTICE file, that is mentioned in the header.

# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You 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.

Is this library really licensed to the ASF or does it just use the Apache license?

[chrismattmann]

Would you like to replace the verbose license header in the other modules with this one-liner as well?

I am unsure if you really need this boilerplate. There is no NOTICE file, that is mentioned in the header.

# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You 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.

Is this library really licensed to the ASF or does it just use the Apache license?

Yes this is the method I've used to include the ASF header in my code since the early days. I think it's fine.