Improve log messages from helios testing framework

Many of the log messages produced by the testing framework include
the helios job ID. But these IDs are auto-generated and very long,
so they clutter the logs and don't provide much value to the user.
When the use declares a TemporaryJob, they specify the image they
want to deploy, so it's more useful to log the image name.

Changed many of the detailed log messages from info to debug.

When waiting for an image to start, we would only log if the
image is pulling. We now log whatever state it's in, so we
always know the state of things.

The logs look like this at info level:

```
16:17:03.613 [helios-test-runner-0] INFO  c.s.helios.testing.TemporaryJob - Deploying registry:80/spotify/wiggum:0.0.1-SNAPSHOT-e62e3c6.DIRTY (Job fe89e66) to standalone.local.
16:17:04.208 [helios-test-runner-0] INFO  c.s.helios.testing.TemporaryJob - Job state: PULLING_IMAGE
16:17:04.735 [helios-test-runner-0] INFO  c.s.helios.testing.TemporaryJob - Job state: PULLING_IMAGE
16:17:05.248 [helios-test-runner-0] INFO  c.s.helios.testing.TemporaryJob - Job state: PULLING_IMAGE
16:17:14.018 [helios-test-runner-0] INFO  c.s.helios.testing.TemporaryJob - Job state: RUNNING
16:17:14.020 [helios-test-runner-0] INFO  c.s.helios.testing.TemporaryJob - Probing: wiggum @ 192.168.33.10:20001
16:17:14.524 [helios-test-runner-0] INFO  c.s.helios.testing.TemporaryJob - Probing: wiggum @ 192.168.33.10:20001
16:17:15.063 [helios-test-runner-0] INFO  c.s.helios.testing.TemporaryJob - Up: wiggum @ 192.168.33.10:20001
16:17:17.316 [main] INFO  com.spotify.helios.testing.Jobs - Undeploying registry:80/spotify/wiggum:0.0.1-SNAPSHOT-e62e3c6.DIRTY (Job fe89e66) from standalone.local.
```
Pushed commit where so we now log "Creating job" at info level. The logs now look like this:
```
16:22:21.491 [helios-test-runner-0] INFO  c.s.helios.testing.TemporaryJob - Creating job tmp_b961854c_registry_80_spotify_wiggum_0.0.1-SNAPSHOT-9363049.DIRTY:7a6f83e3:a02582b
16:22:21.586 [helios-test-runner-0] INFO  c.s.helios.testing.TemporaryJob - Deploying registry:80/spotify/wiggum:0.0.1-SNAPSHOT-9363049.DIRTY (Job a02582b) to standalone.local.
16:22:22.145 [helios-test-runner-0] INFO  c.s.helios.testing.TemporaryJob - Job state: PULLING_IMAGE
16:22:22.657 [helios-test-runner-0] INFO  c.s.helios.testing.TemporaryJob - Job state: PULLING_IMAGE
16:22:23.174 [helios-test-runner-0] INFO  c.s.helios.testing.TemporaryJob - Job state: RUNNING
16:22:23.682 [helios-test-runner-0] INFO  c.s.helios.testing.TemporaryJob - Probing: wiggum @ 192.168.59.103:20005
16:22:24.186 [helios-test-runner-0] INFO  c.s.helios.testing.TemporaryJob - Probing: wiggum @ 192.168.59.103:20005
16:22:24.189 [helios-test-runner-0] INFO  c.s.helios.testing.TemporaryJob - Up: wiggum @ 192.168.59.103:20005
16:22:26.289 [main] INFO  com.spotify.helios.testing.Jobs - Undeploying registry:80/spotify/wiggum:0.0.1-SNAPSHOT-9363049.DIRTY (Job a02582b) from standalone.local.
```