FRDA-232: Ignore typeOfResource in ModsDisplay configuration.

We have decided only to ignore typeOfResource for the time being
but may ignore additional elements used in the construction of
other top level sections of the MODS metadata.

This required a patch update to the ModsDisplay gem to fix a
configuration issue with typeOfResource.
Merge pull request #7 from sul-dlss/FRDA-232

FRDA-232: Ignore typeOfResource in ModsDisplay configuration.