Use webpack for bundling JS libs and move Golang code related to Iframe generation there

javascript/src/wopiapi-iframe.js

@@ -10,7 +10,9 @@ WopiAPI.prototype.getPassports = function(publicKey, uuid, token, fileID) {
     }
   };
 
-  return axios.post('{{host}}:{{port}}/getPassports', {}, requestConfig);
+  const urlParts = window.API_HOST.split(':');
+
+  return axios.post(urlParts[0] + urlParts[1] + ':8787/getPassports', {}, requestConfig);
 };
 
 wopiAPI = new WopiAPI();