Fix logic error when populating task resources.

Bugs closed: AURORA-483

Reviewed at https://reviews.apache.org/r/22007/
Change excludes in rsync commands to avoid unintentionally suppressing non-top-level directories.

Bugs closed: AURORA-491

Reviewed at https://reviews.apache.org/r/22050/
Merge branch 'master' of https://github.com/apache/incubator-aurora
Add argparse as dependency