fixed test-fail
fixed test-fail

checking if "perlbrew lib" prints a usage message doesn't work anymore
because the message is loaded from bin/perlbrew normally while the test
checks lib/App/perlbrew.pm (so the only message coming would be
something about "help for command 'lib' not found".

instead i copied a test from command-alias.t which checks if "perlbrew
lib <unknown-action>" prints a proper error message.

win one, lose one. i guess.

Asuza/App-perlbrew,Asuza/App-perlbrew,josl/App-perlbrew,josl/App-perlbrew,ptolemarch/App-perlbrew,Asuza/App-perlbrew,josl/App-perlbrew,rafl/App-perlbrew,ptolemarch/App-perlbrew,rafl/App-perlbrew,ptolemarch/App-perlbrew,rafl/App-perlbrew