chore(ci): using npm 4 to make it consistent with the dev environment
chore(ci): using npm 4 to make it consistent with the dev environment

jan-molak/serenity-js,jan-molak/serenity-js,red6/serenity-js,jan-molak/serenity-js,red6/serenity-js,jan-molak/serenity-js,red6/serenity-js,red6/serenity-js