fix project_dir determination

update for compatibility with symfony 5 #65

add return values to commands
add symfony 5 instructions to readme

exclude php_executable from directory handling

fixes #48

Merge pull request #57 from zabroc/consumer-user

allow a user property for worker configs

revert clean up as it introduced side-effects

docs (readme): update to reflect bundle version 3 and symfony 4

docs (readme): update to version 2.0

docs (readme): reflect new rabbitmq bundle

fix(worker configuration): remove realpath determination from executa…

…ble path

fix(worker configuration): ensure no leading whitespace