Arvados » Arvados Workbench 2

As a admin I would like to have an access to virtual machines
so that I can see the available VM in the system

Acceptance criteria:
- table with column: uuid, hostname, login
- more options icon (attributes, advanced, remove)

Mockup: https://3czrf1.axshare.com/#g=1&p=15_2_1_admin_panel_-__virtual_machines&c=1