Add Mock tests

[ChunkyProgrammer]

Currently only real tests are done, adding mock tests would be useful in determining whether a test failing is due to a change by us or a change by YouTube and would allow us to test a larger percentage of our code (you can't guarantee that a channel you're testing will always return the same info unless we were to use Mocks)

[ChunkyProgrammer]

This could also help limit the requests we make to YouTube when we are testing