aashto: add set image

Add set image on swagger

src/aashto/src/main/resources/swagger/index.js

@@ -17,8 +17,21 @@ window.onload = function() {
   });
 
   window.ui = ui;
+
+  setImage('logo-img', './drupal/images/logo.b64', 'src');
+  setImage('banner-img', './uswds/img/us_flag_small.b64', 'src');
+  setImage('icon', './favicon.b64', 'href');
 };
 
+function setImage(id, path, attr) {
+  fetch(path)
+    .then(res => res.text())
+    .then(text => {
+      const el = document.getElementById(id);
+      el.setAttribute(attr, text);
+  });
+}
+
 function updateContextPath(contextPath) {
   return {
     statePlugins: {