Allow launching browsers without an Artisan command (for use in queues, etc.)

[tibbsa]

Over the years there have been a number of discussions about using Laravel-Console-Dusk in non-Artisan contexts, e.g. in a queue. I had this need recently and as far as I can tell, the only thing that really prevents people from doing this is the reliance on nunomaduro/laravel-console-task for the pretty-printing of the progress messages.

This PR makes the provision of a Command object optional, and allows Laravel-Console-Dusk to boot even in non-console contexts (by way of a configuration option). In non-Artisan contexts, it will not use laravel-console-task for reporting.

Likely resolves #4 and #17. It seems to be working for our purposes, but I am open to any suggestions on how we might differently architect this.

[eznix86]

hey, @nunomaduro i think this can be merged right ?