Scan only app and spec with rubocop

Should have done this before jumping to a branch. Rubocop shouldn’t
look at any files outside app or spec.
Added the Faker gem and a factories spec

I added the Faker gem and a factories spec to test FactoryGirl. Again,
I should have done this earlier.
Create vote model

I’ve created a vote model with one attribute, :name, a string. This
columns presence is tested in the spec. I also created a factory for
votes with randomly generated names using Faker::Lorem.