Release version 0.4.0
Reworked GitHub workflow script & moved all artifacts to .dev directory:
- Separated OS and PHP version tests (3x3 vs 2x3 matrix)
- Removed php-coveralls from package dependencies & moved its installation to workflow script
- Changed directory for coverage report to
.dev/logs - Fixed cache & simplified setup with ramsey/composer-install GitHub action
- Added env variable to PhpUnit config pointing to
.dev/tests