Write a function that checks whether a letter of the basic Latin alphabet is a vowel. The input is one letter.
Do not consider the letter y a vowel.
Your function should take a Char type value and return a Boolean.
Use the provided code template.
Examples
1) isVowel('a') should be true
2) isVowel('A') should be true
3) isVowel('b') should be false
