Update phpunit config

Small typo in the documentation
Update composer
Update phpunit bootstrap
Introduced Enum class & test
Introduced LogLevel class
Introduced LogHandler class
Introduced Message class
Add File append
Update Settings default file name
PSR fixer
Release 3.1.0
Fix Scrutinizer issues
Fix Enum getOrdinal
Improve code coverage
Update Enum comments
Merge branch 'develop'