allow binaries in vendor folder to be cached

aka: don't delete binaries in node_modules folder, since they shouldn't change anyways (unless the package is also updated)

test/index.js

@@ -14,7 +14,10 @@ it('Hugo exists and runs?', () => {
     // Print additional build environment variables if check successful
     if (works) {
       execFile(hugoBin, ['env'], (error, stdout) => {
-        if (error) throw error;
+        if (error) {
+          throw error;
+        }
+
         console.log(stdout);
       });
     }