Nav-tabs event scoping (#874)

Scope the tab showing behavior to bulkrax views, so that it does not impact unrelated pages

app/assets/javascripts/bulkrax/navtabs.js.erb

@@ -1,7 +1,7 @@
 <% unless defined?(::Hyku) %>
   // enables the tabs in the importers/exporters pages.
   $(document).ready(function() {
-    $('.nav-tabs a').click(function (e) {
+    $('.bulkrax-nav-tab-top-margin.nav-tabs a').click(function (e) {
       e.preventDefault();
       $(this).tab('show');
     });