Added basic up/down voting functionality

  Test are passing.
  May need to provide more test conditions.
```    @vote = Vote.find_or_initialize_by(
      user: current_user,
      review: @review
    )

    if @vote.update(vote_params)
      redirect_to brewery_path(@brewery)
    else
      render template: 'breweries/show'
    end
```