build(deps): bump acorn from 5.7.3 to 5.7.4#2

lneveu merged 1 commit intomasterwebpack/css-minimizer-webpack-plugin:masterfrom

dependabot/npm_and_yarn/acorn-5.7.4webpack/css-minimizer-webpack-plugin:dependabot/npm_and_yarn/acorn-5.7.4Copy head branch name to clipboard