Reactivate investigationId retrieval. It fixes icat/doi-landing-page#55.

www/src/jsonextractor.js

@@ -9,8 +9,7 @@ function JsonExtractor(json) {
  */
 JsonExtractor.prototype.extractInvestigationId = function (data) {
     var regExp = RegExp(/\/\w*-*[Ee][Ss][Rr][Ff]-[Ee][Ss]-(\d+)$/);
-    //return regExp.exec( data.doi )[1];
-    return "investigationId";
+    return regExp.exec( data.doi )[1];
 };
 
 /**