Add Orchestra\Auth\Acl\Fluent::attach() and Orchestra\Auth\Acl\Fluent::detach() method.

Signed-off-by: crynobone <crynobone@gmail.com>
Call Illuminate\Auth\AuthServiceProvider::boot() during booting. Closes #14.

Signed-off-by: crynobone <crynobone@gmail.com>