efine a function called fewest_coins that accepts a floating point dollars amount as argument, and returns an integer equal to the minimum number of coins required to give change in that amount.
For full credit, your solution must use the coin_change function your previously defined
Remark: Since the "greedy" strategy for giving change (already implamented by coin_change) is optimal
fewest_coins simply needs to return the sum counts in coin_change (dollars)
Practice goal: Short exercise in code re-use and program structure; can be written as a one-linier