launch_xvfb - display and dimensions should be instance variables

[ShockwaveNN]

No description provided.

[leonid-shevtsov]

I'm actually consciously using the public interface to access those instance variables there.

[ShockwaveNN]

If so - you probably should change func
def attach_xvfb
possible_display_set = @autopick_display ? @display..MAX_DISPLAY_NUMBER : Array(@display)
pick_available_display(possible_display_set, @reuse_display)
end
to use interface instead of @display

[abotalov]

I think it can be closed as it's refactored in #46