Stream build logs while waiting for job to finish

[agis]

This could look like this:

$ mistry build --project foo --stream-output
Building zxc...
Building abc...

[apostergiou]

#65 introduced a --verbose flag for this functionality, so I think we can resolve this.

[apostergiou]

On a second thought this issue is more about streaming while the job is building, while the --verbose displays the logs only when the job has finished.