deposit: workflow integration changes
deposit: workflow integration changes

* Updates the Deposition and DepositionType classes to use
  newer workflows object bound API.

Signed-off-by: Jan Aage Lavik <8d55e006a1b29770f275a5c59a7341f17f8e69d5@cern.ch>

inveniosoftware/invenio-deposit,inveniosoftware/invenio-deposit,inveniosoftware/invenio-deposit,inveniosoftware/invenio-deposit