Add a link to generate a new bearer token

https://www.pivotaltracker.com/story/show/69285272

[#69285272]

- The link warns the user if there is already a bearer token set

## Warning
There are a couple of things I'm unsure of with this.
- Frontend is not my forte
- I'm unsure about the Django asset management. It seems to work even when I use the production settings which as far as I understand it should not.