Add slumber dependency for storage-service

Refs #5427
Merging fix for issue #5159

Squashed commit of the following:

commit e0e35f110813039fed2cb2e8cb8b075717c09d95
Author: Misty De Meo <mdemeo@artefactual.com>
Date:   Thu Sep 19 16:17:01 2013 -0700

    Pointer file: nest transformFile under file, refs #5159

    This was being incorrectly parented under FLocat, which has no children.

commit c6255180ac660140c9dee925f7725dc5b0eaeb89
Author: Misty De Meo <mdemeo@artefactual.com>
Date:   Thu Sep 19 15:55:04 2013 -0700

    Pointer file: fix namespaces, refs #5159

    This resolves two of the errors flagged by http://pim.fcla.edu/validate.
fixing sampledata import for #5622

dev-helper now correctly updates archivematica-sampledata from github.com