[db] Create :reviews table
Set up association between User, Translation and Review
Display review-er on translation index page
[db] add timestamp for :reviews & :translations
Display reviews_link on translations index page
Update validation for :review & :translation
ActiveModel::Errors # to_flash

- well-formatted model error display in flash
Handle review update
[chore] use symbol instead of instance variable in form

- for re-usability
[view] translator_dashboard
Merge pull request #8 from Gecko-Gecko/set-up-review-model

Set up Review Model