#573 Throw new Error when version can't be downloaded (#596)

* get fallback version if bundle is not available for wanted platform

Meant to fix #589

* Linting compute-download-urls.js

* Throw new Error when version can't be downloaded

This is meant to fix #573

Author: lthurr

lib/install.js

@@ -315,6 +315,7 @@ async function install(_opts) {
           } else {
             reject(logError('getDownloadStream', err, 'Could not download ' + downloadUrl));
           }
+          throw new Error('Could not download ' + downloadUrl);
         });
     });
   }