There are three types of edits that can be performed on strings: insert a character,
remove a character, or replace a character. Given two strings, write a function to check if they are
one edit (or zero edits) away.
EXAMPLE:
pale, ple -> true
pales, pale -> true
pale, bale -> true
pale, bake -> false
from Cracking The Coding Interview - Interview Question 1.5