This commit:
*  Adds a GH Actions workflow for the CI checks which were previously run on Travis as the default test script.
    Includes only running the base tests for the builds using custom ini setting.
* Removes the, now redundant,  `.travis.yml` configuration.
* Remove the custom PHP ini configurations.
    Setting these is now handled in the script itself.
* Updates the `.gitattributes` file.
* Updates the  "Build Status" badge in the Readme to use the results from the GH `Test`  Actions runs.