Specify default VirtualHost on the command line

[Matthew-Davey]

When using a virtual host other than default ('/'), it needs to be specified for most operations eg.

Declare.Exchange("myExchange")
       .OnVirtualHost("NotDefault")

Declare.Queue("myQueue")
       .OnVirtualHost("NotDefault")

It would be good if we could override the default VirtualHost on the command line eg.

EasyNetQ.Migrations.Runner.exe -hostUrl localhost -username guest -password guest -vhost NotDefault MyProject.RabbitMigrations.dll