Add spec for dice roll service
user
```ruby
require 'rails_helper'

RSpec.describe RollDice, type: :service do
  let(:game_params) { { number_of_players: 2 } }
  let(:game) { Game.create!(game_params) }

  let(:user) { User.create!(username: "user") }
  let(:piece) { "wheelbarrow" }

  let(:player) { game.players.create!(user: user, piece: piece) }

  subject(:service) { RollDice.new(game: game, player: player) }

  context "when it is my turn" do
    # TODO how do we set up my turn?, override what game does

    describe "rolling the dice" do
      it "succeeds" do
        expect(service.call).to be_truthy
      end

      it "adds a dice roll" do
        expect { service.call }.to change(DiceRoll, :count).by(1)
      end

      it "adds the dice roll to the correct game" do
        service.call
        expect(DiceRoll.last.game).to eql game
      end

      it "adds the dice roll to the correct player" do
        service.call
        expect(DiceRoll.last.player).to eql player
      end

      it "has a valid dice roll" do
        service.call
        expect(DiceRoll.last.amount).to be_present
        expect(DiceRoll.last.amount).to be < 7
        expect(DiceRoll.last.amount).to be > 0
      end

      it "has no errors" do
        service.call
        expect(service.errors).not_to be_present
      end
    end
  end

  context "when it is not my turn" do
    # TODO how to set up?, this should fail
  end
end
```
assistant