Fix bug that skips rendering single contributors

** Why are these changes being introduced:

Our rendering of contributors from TIMDEX apparently has a bug that
skips rendering anything if there is only one contributor on the record.

** Relevant ticket(s):

* https://mitlibraries.atlassian.net/browse/use-214

** How does this address that need:

This adds an .each call to the .uniq filter that exists, which forces
Rails to actually process the single resulting record in the case of a
single contributor being present on the record.

** Document any side effects to this change:

Hopefully none.

Author: matt-bernhardt

app/views/shared/_contributors.html.erb

@@ -1,5 +1,5 @@
 <%= return if contributors.blank? %>
 
-<% contributors.uniq do |contributor| %>
+<% contributors.uniq.each do |contributor| %>
   <li><%= link_to contributor['value'], results_path({ advanced: true, contributors: contributor['value'] }) %></li>
 <% end %>