fix more properly #48 after reading path.parse documentation more thoroughly

lib/persistence.js

@@ -375,7 +375,7 @@ class Persistence {
   static async ensureDirectoryExistsAsync (dir, mode = DEFAULT_DIR_MODE) {
     const parsedDir = path.parse(path.resolve(dir))
     // this is because on Windows mkdir throws a permission error when called on the root directory of a volume
-    if (process.platform !== 'win32' || parsedDir.dir !== parsedDir.root) {
+    if (process.platform !== 'win32' || parsedDir.dir !== parsedDir.root || parsedDir.base !== '') {
       await storage.mkdirAsync(dir, { recursive: true, mode })
     }
   }