Rollout stats/graph page

[b-rowan]

Do we want to add a page for each rollout, which would be accessed from the rollouts table (similar to how device logs are accessed), and would show more in depth stats about the rollout, along with some graphs?

Main issue here is deciding on a chart library, so I want to start here with discussion around what chart library we should use, then move to implementing this.

[tsagadar]

Currently we don't store much data in the DB - just success/failure counts for each rollout. So not much graphing that could be done based on this.