Create a function that finds the word "bomb" in the given string (not case sensitive). If found, return "Duck!!!", otherwise return "There is no bomb, relax.".
bomb("There is a bomb.") ➞ "Duck!!!"
bomb("Hey, did you think there is a bomb?") ➞ "Duck!!!"
bomb("This goes boom!!!") ➞ "There is no bomb, relax."
"bomb" may appear in different cases (i.e. uppercase, lowercase, mixed).