Bump webpack-dev-server from 2.11.5 to 3.1.11 in /test/dummy_sprockets#1012

BookOfGreg merged 1 commit intomasterreactjs/react-rails:masterfrom

dependabot/npm_and_yarn/test/dummy_sprockets/webpack-dev-server-3.1.11reactjs/react-rails:dependabot/npm_and_yarn/test/dummy_sprockets/webpack-dev-server-3.1.11Copy head branch name to clipboard