tools: update release.sh to work with new website

now need to specify "nodejs" or "iojs", also remove .gpg file

PR-URL: https://github.com/nodejs/node/pull/2623


Reviewed-By: jbergstroem - Johan Bergström <bugs@bergstroem.nu>

cherry-picked by @rvagg to v3.x, s/nodejs/iojs/