caesarEncrypt

Caesar cipher is a more advanced substitution cipher than Atbash cipher. Caesar cipher shifts all the letters in the alphabet by a certain amount, and then substitutes the letters with the ones on positions i + s, where i is the index of the original letter, and s is the shift number. The shift number is found out by computing shift % alphabet.size, where shift is the desired shift by the user and alphabet.size is the number of letters in the alphabet.