Upvote

Resolves all 4 parts of Issue #3 
Resolves part 2 of Issue #10 
Resolves all 3 parts of Issue #11 
You can probably consolidate the `create` and `update` action into `create`:

```ruby
def create
  review = Review.find(params[:review_id])
  vote = Vote.find_by(review: review, user: current_user)
  vote ||= View.new(review: review, user: current_user)
  vote.assign_attributes(vote_params)
  vote.save

  redirect_to review.food_truck
end
```