Update CHANGES with latest fixes
Digest::SHA v5.74+ only works on encoded strings.

MD5/SHA operate on a string of bytes (string of chars with values in 0..255). It cannot operate on text or other strings that that may contain chars larger than a byte. You must serialize those first. For text, one might serialize using UTF-8.

See: http://www.nntp.perl.org/group/perl.perl5.porters/2012/11/msg195553.html

Closes #4
Remove all mention of Digest::PBKDF2

This module is never likely to be updated to a state that is usable in D::P::Passphrase.
Count the number of tests correctly
Travis CI needs this extra info to test properly
Add Travis CI support
Remove debugging cruft