v2 OAI server needs additional namespaces

[ghukill]

Some work on DPLA aggregator showed that the python lxml library cannot perform XSLT transformations on records coming out of the v2 OAI server.

They should look like this:

<record xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://www.openarchives.org/OAI/2.0/">
    <header>
        <identifier>oai:digital.library.wayne.eduwsudor_dpla:oai:digital.library.wayne.edu:wayne:ws88.21</identifier>
        <datestamp>2017-07-07</datestamp>
        <setSpec>wsudor_dpla</setSpec>
    </header>
    <metadata>
        <mods:mods xmlns:xlink="http://www.w3.org/1999/xlink"
            xmlns:xl="http://www.w3.org/1999/xlink" xmlns:mets="http://www.loc.gov/METS/"
            xmlns:mods="http://www.loc.gov/mods/v3">

But ours look like this:

<record>
    <header>
        <identifier>oai:digital.library.wayne.edu:wayne:ws88.21</identifier>
        <datestamp>2017-05-15</datestamp>
    </header>
    <metadata>
        <mods:mods xmlns:mets="http://www.loc.gov/METS/" xmlns:xl="http://www.w3.org/1999/xlink"
            xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink">

Most noticeably, missing the xmlns="http://www.openarchives.org/OAI/2.0/" from the <record> element.