Bump json5 and rollup-plugin-babel in /webcomponentsjs#24

dependabot[bot] wants to merge 1 commit intomasterwrlab/polymer-elements:masterfrom

dependabot/npm_and_yarn/webcomponentsjs/json5-and-rollup-plugin-babel-2.2.2wrlab/polymer-elements:dependabot/npm_and_yarn/webcomponentsjs/json5-and-rollup-plugin-babel-2.2.2Copy head branch name to clipboard