Add Animal Location Dropdown in Animal Registration Form

[cjgochanour]

In AnimalForm.js

The code mostly works in its current state. It will work completely when issue #17 is resolved.

As a stretch goal, we would like to filter the employees by the customer's selected locationId.

• [ ] Add a <div> in the form for the user to select a location from a <select> dropdown
• [ ] Need to add a state variable to keep track of the selected locationId
• [ ] Filter the employees state array by the selected locationId

Related to issue #9