test: Add basic UI for viewing and restarting builds

I was finding myself continually scrolling through the runner log file to see if builds had failed and to grab their log urls, so I've added a very basic UI for viewing builds, with the added function of being able to restart builds.
```go
return tx.Bucket([]byte("builds")).Put([]byte(b.Id), val)
```

I'd also make a global var for `[]byte("builds")` and any other bucket keys.