RFR Cp add votes

issue #10 
This `before :each` really only needs to get run before the first test in this `context` block, so I'd probably get rid of it.  Also, the second spec in this `context` block actually does involve an authenticated user, so I wouldn't include it in the `unauthenticated user` context:

```ruby
  context "unauthenticated user" do
    scenario "cannot delete review if not logged in" do
      visit bus_path(bus)
      expect(page).to_not have_content "Delete"
    end
  end

  context "authenticated author of the review" do
    before :each do
      FactoryGirl.create(:vote, review: review)
      sign_in_as(review.user)
      visit bus_path(bus)
    end

    scenario "delete review from the bus detail page" do
      expect { click_link "Delete" }.to change(Review, :count).by(-1)
    end

    scenario "deleting a review deletes all associated votes" do
      expect { click_link "Delete" }.to change(Vote, :count)
    end
  end

  scenario "only user can delete its own review" do
    user = FactoryGirl.create(:user)
    sign_in_as(user)
    expect(page).to_not have_content "Delete"
  end
```