Translations variable change to object

Translations is referenced with i18n.translations[lang][str],
so it should be changed to be an object.

I think it should be used something like below.

e.g.
translations: {
    kr:{
      'Please fill in a headline': '빈칸 채우라고'
    }
  }
Merge pull request #286 from nicejwjin/patch-1

Translations variable change to object