Fifo animal shelter

[mts513]

• Can successfully enqueue a Dog
• Can successfully enqueue a Cat
• Error handling when you try to enqueue something that is neither a Dog nor a Cat
• Can successfully dequeue a Dog
• Can successfully dequeue a Cat
• Can successfully dequeue the front of the AnimalShelter queue when you pass no parameters to dequeue
• Error handling when you try to dequeue something that is neither a 'cat', 'dog' or an empty string
• Can successfully print the resulting object from a dequeue action