Write a method isPalindrome that takes a String as a parameter and that

returns true if the String is a palindrome and that returns false

otherwise. A String is considered a palindrome if it has the same

sequence of letters when reversed (e.g., "radar", "toot", "mom", "a").

By definition, the empty string is considered a palindrome. Your

method should ignore the case of letters in determining whether it is a

palindrome (e.g., "Mom" and "RAdar" should be considered palindromes)