Fix Psysh command execution (#72)

Note on unnecessary installation step on symfony 5 (#59)

maybe also not needed on symfony 4 (?).

Misc update (#55)

- Fix some CS
- Add types
- Copy the necessary test container services from `test.xml` instead of prepending the framework bundle test config
- Make `psysh.shell` private
- Inject the Psysh application instead of application child class
- Add a few missing `@private` tags

Remove deprecated Symfony\Component\Debug (#50)

Allow symfony 5 (#48)

Upgrade config for Symfony 4.3 TestContainer (#44)

Fix root node deprecation in symfony-config (#42)

Lazily load the command (#39)

Add support for PsySH v0.9 (#37)

Make psysh.facade public so it is not removed from the compiled conta…

…iner (#31)

- Update PHPUnit to 6.x
- Move `AppKernel` in a namespace and leverage the Composer PSR-4 autoloader and the `KERNEL_CLASS` environment variable
- Make the necessary services public
- Fix bin/console AppKernel usage and permissions