Parse degree info (masters/doctoral) and set resource_type

[kerchner]

ProQuest xml contains a DISS_description tag which we can use when creating the GwEtd work to set resource type to more specific values, such as Master's Thesis or Dissertation.

Examples:

<DISS_description page_count="112" type="doctoral" external_id="http://dissertations.umi.com/gwu:12345" apply_for_copyright="no">

<DISS_description page_count="" type="masters" external_id="http://dissertations.umi.com/gwu:12345" apply_for_copyright="no">