There were identical specs in ephemera folders controller, coins
controller, and scanned resources controller specs. This will make
them easier to change together
The shared spec for ResourcesController had the pdf spec, but the
ResourcesController does not implement that code, it's directly in the
scanned resources controller itself, so it didn't make sense for the
spec to be there.
Set us up to move the pdf controller code to a concern
refs #6278