You got it correctly, but it seems that there is something wrong. Please check your API key usage on https://code.google.com/apis/console/
Make sure it is correct and that it translates fine: https://www.googleapis.com/language/tra ... leResponse
If it is OK you will get the translation of flowers in French, otherwise it will show badRequest error or something else.
If it is OK, upload info.php file from the package into gtranslate folder and let me know.