TSLINT indicates TS2321 and TS2345

`app.use(VueCookieNext);`

TSLINT check indicates several errors in this line of code.

```
TS2321: Excessive stack depth comparing types 'IVueCookieNext' and 'Plugin_2'.
TS2345: Argument of type 'IVueCookieNext' is not assignable to parameter of type 'Plugin_2'.
```

Although I can ignore it, I think it's better to solve it