ruby/simple-cipher (#1)
ruby/simple-cipher (#2) remove duplications
ruby/simple-cipher (#3) random key generation
ruby/simple-cipher (#4) a little more compact
ruby/luhn (init)
ruby/luhn (#1)
ruby/pig-latin (init)
ruby/pig-latin (#1)
ruby/pig-latin (#2) common find_prefix
ruby/pig-latin (#3) move find_prefix to String
ruby/pig-latin (#4) ignore all vowels