Remove license from readme
Remove license from readme

LICENSE already exists as its own file (https://github.com/sstephenson/ruby-build/blob/master/LICENSE)
dark-panda/ruby-build,znz/ruby-build,pongstr/node-build,rbenv/ruby-build,makandra/ruby-build,brigade/ruby-build,nirvdrum/ruby-build,dark-panda/ruby-build,jeremy/ruby-build,sstephenson/ruby-build,telstra-digital/ruby-build,mpalmer/puppet-module-ruby-build,liquid/ruby-build,Angeldude/ruby-build,jasonkarns/ruby-build,ryanfb/ruby-build,keltia/ruby-build,mpalmer/puppet-module-ruby-build,OiNutter/node-build,geoffharcourt/ruby-build,rbenv/ruby-build,nodenv/node-build,brigade/node-build,brigade/ruby-build,deepj/ruby-build