backend/jb: print more info on boot timeouts (#207)
backend/jb: print more info on boot timeouts (#207)

* backend/jb: print more info on boot timeouts

* backend/jb: handle context cancel in boot wait loop

* backend/jb: use context to cancel dialer

* backend/jb: wait for 2 seconds for error from timeout

The Dial timeout is 1 second, so we should wait for longer than that.

* Use if instead of select to detect if context is done

This is functionally the same, but I think it's a bit easier to understand the
newer version.

* backend/jb: make timeouts configurable

travis-ci/worker,travis-ci/worker,travis-ci/worker