Commands inside tinker incorrectly parsed

[amadeann]

Steps To Reproduce:

1. Open psysh
2. type exit

Expected: Tinker closes with Exit: Goodbye
Actual: RuntimeException with message 'Too many arguments, expected arguments "command".'

From what I see, it most likely caused by the change in symfony/console (line 27) commited 10 days ago:
symfony/console@aa58a69

Because of that change Psy\Input\ShellInput::tokenize() is not able to correctly parse arguments. Instead of catching the entire "exit" string, it parses it letter by letter.

[amadeann]

Posted it here by mistake (I initially thought it was a bug in tinker). See the issue for reference: bobthecow/psysh#704