Remove Deprecations Warnings

[pgwillia]

Describe the bug
We've forked and pinned our blacklight dependencies. Now we can remove all the Deprecation Warnings that are cluttering our logs and making them unreadable.

To Reproduce
Steps to reproduce the behavior:

1. Start the rails server rails s
2. Do a random walk of [localhost:3000]
3. Review the logs
4. See deprecation warnings galore!

Expected behavior
Only get actionable content from the logs.

Additional context

DEPRECATION WARNING: Building search parameters by calling show_only on CatalogController. This behavior will be deprecated in Blacklight 6.0. Instead, define show_only on a subclass of SearchBuilder and set search_builder_class in the configuration. (called from each at /home/pgwillia/.asdf/installs/ruby/2.5.8/lib/ruby/gems/2.5.0/bundler/gems/blacklight-0a1073122697/lib/blacklight/search_builder.rb:141)
DEPRECATION WARNING: Calling #refworks_export_url without a :url is deprecated. Pass in e.g. { url: url_for_document(@document, format: :refworks_marc_txt) } instead. (called from _app_views_catalog__show_sidebar_html_erb___1983130472754068703_69810748924640 at /mnt/c/Users/pgwillia/Code/ualbertalib/discovery/app/views/catalog/_show_sidebar.html.erb:46)