[DLFL23] 14-truck_backer_upper.ipynb - Fix oudated matplotlib API usage

[dqian3]

Was trying to get the truck backer upper working as shown in the NYU Deep Learning class, but rather than downgrade jupyter and matplotlib, I figured out what needed to be changed to make the the notebook work with the latest version.

Tested with a fresh conda install, but haven't tried the other notebooks.

Summary of changes:

• Remove old positional argument in matplotlib.patches.Rectangle
• Replace pylab imports with python random and math modules.
• truck_backer-upper => truck_backer_upper
• Add ipympl and use %matplotlib notebook