Adding animalGender and animalWeight options

Adding options to set animalGender and animalWeight. Also made
animalWeight hidden by default (only used if the animal is a dog).
Weight appears when Dog is selected.
animalWeight is updated as it is entered

animalWeight now updates as the user enters numbers, to prevent the user
from needing to press enter for the weight to save into the
animalObject.
animalWeight fades in and animalObj grows

When a dog is selected, the animalWeight field fades into the form, and
the animalObject grows to accommodate it.