Update in prep for Jruby 9000, replace Digest::HMAC with OpenSSL::HMAC etc.

[guyboertje]

the code is easy to replace but in the specs there is some hand encoded payloads that are not compatible with the OpenSSL impl, i.e. two specs fail.

[ph]

I moved to the new jruby 9k classes, but like @guyboertje said the test are failling. I am treating this a as regression for now since the payload seems to be a dump of an actual collectd communication or frame.