chore(package): update npm to version 3.8.1
chore(package): update npm to version 3.8.1

http://greenkeeper.io/
pnpm/supi,rstacruz/pnpm,andreypopp/pnpm,pnpm/pnpm,pnpm/pnpm,andreypopp/pnpm,pnpm/supi,pnpm/supi,andreypopp/pnpm,rstacruz/pnpm,rstacruz/pnpm,pnpm/pnpm