Create ps2-2.splay.py

# TASK:
#
# This is the SplayTree code we saw earlier in the 
# unit. We didn't achieve full statement coverage 
# during the unit, but we will now!
# Your task is to achieve full statement coverage 
# on the SplayTree class. 
# 
# You will need to:
# 1) Write your test code in the test function.
# 2) Press submit. The grader will tell you if you 
#    fail to cover any specific part of the code.
# 3) Update your test function until you cover the 
#    entire code base.
#
# You can also run your code through a code coverage 
# tool on your local machine if you prefer. This is 
# not necessary, however.
# If you have any questions, please don't hesitate 
# to ask in the forums!