Arvados » Arvados Workbench 2

As a user I would like to have an access to repositories and also create a new one
so that I will have the repositories resource lists

Acceptance criteria:
- button for creating new repository
- help icon with model (at. repositories - help) (SSH access - https://doc.arvados.org/user/getting_started/ssh-access-unix.html; Writting a Crunch Script - https://doc.arvados.org/user/tutorials/tutorial-firstscript.html)
- table with column: name, URL
- more options icon (attributes, share, advanced, remove)
- "add an SSH key to your account" moved to SSH Keys page

Mockup: https://3czrf1.axshare.com/#g=1&p=15_1_1_admin_panel_-_repositories&c=1

Endpoint docs: https://doc.arvados.org/api/methods/repositories.html