Get job logs

[annisele]

As mentioned here https://github.com/Azure/aztk/pull/278, logs are updated to azure blog storage only after app is completed.

I noticed that even after stopping an app, the job finished in a completed state but the logs never show up. This makes it really hard to debug failing jobs. Can we get streaming logs (great for longer spark jobs) or at least all output should be written at the end?