Allow support for SolrWrapper 2.x
Allow support for SolrWrapper 2.x

SolrWrapper 2.0 was released in
https://github.com/cbeer/solr_wrapper/commit/4c412aba182a33c28fddf77736f86d7c8c304102.

This deals with changes in apache's checksum publishing practices. We keep
support for 1.0 for backwards compatibility, though some downstream adopters may
find they need to upgrade to keep SolrWrapper working.

samvera/hyrax,samvera/hyrax,samvera/hyrax,samvera/hyrax