Fix API

[ayojackay]

Describe the bug
The Cat API is no longer working; we're in need to update the curriculum API to another that works

To Reproduce
Steps to reproduce the behavior:

1. Visit JS Curriculum
2. Click on 'Day Six' from the Lessons nav
3. Scroll down to the 'Take Home Challenge' section, and click on Cat API
4. See the error

Expected behavior
Clicking on API to use for assignment should take you to a site where an API works