Updating site to use USWDS styles (#509)

* Updated header and footer
* Updated fonts
* Moved files around and updated gulpfile to correct the build process when it goes to production
* Adjusted grid templating
* Added images to assets
* Update app/templates/components/uk_components/footer/template.njk

Co-authored-by: Steven Reilly <stvnrlly@users.noreply.github.com>

app/templates/views/send-test.html

@@ -39,7 +39,7 @@
       {% endif %}
     </div>
     {% if link_to_upload %}
-      <p class="govuk-body">
+      <p>
 
       </p>
     {% endif %}