Trouble installing logstash kv filter plugin

Hi Logstash Community!

I am learning to use the ELK stack and currently trying to install the kv
filter plugin for logstash but nothing seems to work for me. I first tried
to install filter plugins manual following the foo.rb hello world tutorial.
I later discover that in logstash 1.5.0 there is a new way to installing
plugins using "bin/plugin install," but its giving me this message, "Can
only install contrib at this time... Exiting."

Is it possible to install filter plugins at this point for logstash 1.5.0?
if it is, can someone be so kind to point me to the right tutorial?

Thanks,
Donald

This message only occurs with Logstash 1.4.x, not Logstash 1.5.0. Are you certain you're running Logstash 1.5.0? What is the output of bin/logstash version ?