- Removed links to the gov uk stylesheets

- Deleted /stylesheets folder
- Removed sass build from gulpfile
- Changed gov links to usa links
- Changed other govuk styles, like breadcrumbs
- Changed name of uk_components file to us_components
- Fixed a few tests that broke on account of the changes

app/templates/views/dashboard/_upcoming.html

@@ -6,7 +6,7 @@
     <h2 class="heading-medium heading-upcoming-jobs">
       In the next few days
     </h2>
-    <a class="govuk-link govuk-link--no-visited-state banner-dashboard" href="{{ url_for('.uploads', service_id=current_service.id) }}">
+    <a class="usa-link banner-dashboard" href="{{ url_for('.uploads', service_id=current_service.id) }}">
       <span class="banner-dashboard-count">
         {{ current_service.scheduled_job_stats.count }}
       </span>