Stock App Homework

App is almost complete minus a UI for selling stock. The function itself works, but I ran out of time to finish the user interface.
I didn't use all of the exact stocks listed in the exercise because many of them did not appear to be real stocks and I wanted to use YahooFinance for all.
I'm quite pleased with both the buy_stocks and sell_stocks methods and also the Print Snapshot function.
Print Snapshot I wanted to make look like the 'tree' command in terminal but could not make this work exactly as to do this, I needed a way to know when I had reached the last iteration when using .each.