Code review comment for lp:~evarlast/charms/trusty/mongodb/fix-dump-actions

Thank you for your work on this.

While I realize that the test race wasn't introduced by your proposed changes, please see:
https://bugs.launchpad.net/charms/+source/mongodb/+bug/1518468

It would be awesome to resolve that test issue along with this, as it's definitely presenting a pain point.