- 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/components/service-link.html

@@ -1,6 +1,6 @@
 {% macro service_link(service, endpoint, link_text) %}
   {% if service %}
-    <a class="govuk-link govuk-link--no-visited-state" href="{{ url_for(endpoint, service_id=service.id) }}">{{ link_text }}</a>
+    <a class="usa-link" href="{{ url_for(endpoint, service_id=service.id) }}">{{ link_text }}</a>
   {% else %}
     <b class="govuk-!-font-weight-bold">{{ link_text|capitalize }}</b>
   {% endif %}