Adds a randomRecipe

Now you can get a random recipe and a random recipe filter by category,
using a CategoryId

Close #30
Close #31
Adds new parameters on getRecipe request.

Adds parameters, IngredientId, TypeId, and Average on method getRecipe
Modifies a randomRecipe, now randomRecipe is randomRecipeId and request
only RecipeId.
Update EER digram adding a Average on Recipe