Encrypting and Decrypting a message

In cryptography, character shifting encryption, or Caesar cipher, is used by Julius Caesar who led the Roman Empire.

For example, the character E shifted backwards by 3 characters would be B.

So, the word "Hello" with each character shifted backwards by 3 characters would be "khoor".

Use String methods .ord to convert find the integer ordinal of a string and .chr to convert integer ordinal back to string.

> "H".ord
> # => 72
> 72.chr
> # => "H"

Your assignment

1. Write a function to encrypt a message (by shifting char code up or down)
2. Write a function to decrypt a message

Example:

encrypt("hello")
# => "ifmmp"

decrypt("ifmmp")
# => "hello"

def encrypt(message)
  # your answer
end

def decrypt(message)
  # your answer
end