docs(README) update README with new jspm version
docs(README) update README with new jspm version

topheman/vanilla-es6-jspm,Andersos/vanilla-es6-jspm,felquis/vanilla-es6-jspm,topheman/vanilla-es6-jspm,Andersos/vanilla-es6-jspm,felquis/vanilla-es6-jspm,felquis/vanilla-es6-jspm,topheman/vanilla-es6-jspm,Andersos/vanilla-es6-jspm