Varchar overflow in comments model bugfix

https://semaphoreapp.com/fs/rails-base-api/branches/some-code-refactoring/builds/2

Failure/Error: let!(:comment) { FactoryGirl.create :comment, user: user }
     ActiveRecord::StatementInvalid:
       PG::StringDataRightTruncation: ERROR:  value too long for type character varying(255)
       : INSERT INTO "comments" ("created_at", "text", "title", "updated_at", "user_id") VALUES ($1, $2, $3, $4, $5) RETURNING "id"