Symfony 4.x compatibility
update symfony version to ^3.4|^4.0 (#2) * update symfony version to ^3.4|^4.0 * add github action workflow * remove preceding "dot" in ".workflow" * add missing ci-test script definition * remove travis-ci
update symfony version to ^3.4|^4.0 (#2) * update symfony version to ^3.4|^4.0 * add github action workflow * remove preceding "dot" in ".workflow" * add missing ci-test script definition * remove travis-ci