Queue Class

LockedIn uses a Queue to keep track of the order that recruiters should use to reach out to job seekers.

Implement the following operations on the Queue class:

• queue.push(item): Adds an item to the tail of the queue (index 0 of list)
• queue.pop(): Removes and returns an item from the head of the queue (last index of list)
• queue.peek(): Returns an item from the head of the queue
• queue.size(): Returns the number of items in the queue

Note: You'll often hear words used interchangeably in programming. For example, here we're saying push and pop, but enqueue and dequeue are also common words for the same ideas.

• The underlying data type we're using is just a List. Don't forget to guard against IndexErrors by returning 'None' if the queue is empty.
• The .insert List method may be helpful.