refactoring encrypted_response to use new GnuPG class
implemented GnuPG.has_public_key_with_uid (#3)
more refactoring to use new GnuPG class (#3)
bug with importing attached keys
GnuPG class now creates homedir if it doesn't exist
turns out = chars in MIME-encoded email get "quoted-printable", so I had to decode them
removed debug print statement