fix: 🐛 key type check doesn't work for Object.entires([])

`Object.entires()` always yields string for number keys

✅ Closes: #54

Author: mpyw

package.json

@@ -1,6 +1,6 @@
 {
   "name": "axios-case-converter",
-  "version": "1.0.0",
+  "version": "1.0.1",
   "main": "lib/index.js",
   "module": "es/index.js",
   "types": "typings/index.d.ts",

src/transformers.ts

@@ -105,7 +105,7 @@ const transformObjectUsingCallbackRecursive = (
     if (isFormData(store) || isURLSearchParams(store)) {
       store.append(fn(key as string), value as string & File);
     } else if (key !== '__proto__') {
-      store[typeof key === 'number' ? key : fn(`${key}`)] =
+      store[Array.isArray(data) ? Number(key) : fn(`${key}`)] =
         transformObjectUsingCallbackRecursive(value, fn, overwrite);
     }
   }