Moving on from tossing a single coin in the last lesson, let's now toss two coins. What we'll do here is to see how many times heads comes up on both coins (HH) versus something different (like HT, TH, or TT).

We'll start by streamlining the code by making a function called toss() which handles all of the tossing mechanics of a coin, just returning a 'h' for heads or 't' for tails.