Add TruffleRuby 1.0.0-rc8
Add TruffleRuby 1.0.0-rc8

dark-panda/ruby-build,sstephenson/ruby-build,rbenv/ruby-build,dark-panda/ruby-build,nodenv/node-build,brigade/node-build,brigade/ruby-build,brigade/ruby-build,makandra/ruby-build,mpalmer/puppet-module-ruby-build,ryanfb/ruby-build,mpalmer/puppet-module-ruby-build,OiNutter/node-build,rbenv/ruby-build