Prepare the plugin for localization

Hi @mythemeshop, thank you for the plugin!

We translated your plugin to Russian https://translate.ww.wp.xz.cn/locale/ru/default/wp-plugins/wp-review.

But there is error: Your plugin slug is wp-review, but there seems no Text Domain: defined in wp-review.php! To correctly internationlize your plugin you will need it.

Could you please fix this to prepare the plugin for localization? Thanks!