As a Project Member on a deliverable view I can add deliverable sources to be used in a set of deliverable items

https://projects.invisionapp.com/d/main#/console/12114617/283318985/preview
On a deliverable view, I need to expand the deliverable sources area where I can drag and drop files to the "deliverable sources" area to upload them to the deliverable. using the same pattern we've seen on project create/background docs and project sources).

AC:

• a user can drag and drop binaries
• a user can open a dialog to add new binaries
• if there is no content, a '+' is displayed
• if there is content, the '+' goes away