- 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/file-upload.html

@@ -1,4 +1,4 @@
-{% from "components/uk_components/button/macro.njk" import govukButton %}
+{% from "components/us_components/button/macro.njk" import govukButton %}
 
 {% macro file_upload(
   field,
@@ -34,7 +34,7 @@
     </label>
     {% if alternate_link and alternate_link_text %}
       <span class="file-upload-alternate-link">
-        or <a class="govuk-link govuk-link--no-visited-state" href="{{ alternate_link }}">{{ alternate_link_text }}</a>
+        or <a class="usa-link" href="{{ alternate_link }}">{{ alternate_link_text }}</a>
       </span>
     {% endif %}
     <label class="file-upload-filename" for="{{ field.name }}"></label>