More test updates; docker steps for local testing

README.md

composer.json

docker/config/authsources.php

docker/config/config-override.php

lib/HTTPLocator.php

lib/OAuth2ResponseHandler.php

lib/OIDCLogoutHandler.php

tests/lib/Auth/Source/OpenIDConnectTest.php

tests/lib/Auth/Source/OrcidOIDCAuthTest.php

tests/lib/OAuth2ResponseHandlerTest.php

tests/lib/OIDCLogoutHandlerTest.php

tests/lib/Providers/AdjustableGenericProviderTest.php

tests/lib/Providers/OpenIDConnectProviderTest.php