Bump acorn from 5.7.3 to 5.7.4 in /packages/client-js#2

dependabot[bot] wants to merge 1 commit intomastercollaboratory/candor:masterfrom

dependabot/npm_and_yarn/packages/client-js/acorn-5.7.4collaboratory/candor:dependabot/npm_and_yarn/packages/client-js/acorn-5.7.4Copy head branch name to clipboard