Build error with instantsearch.js/facet-dropdown

Hi,

After npm install, npm start return following error :

Server running at http://localhost:3000
🚨 /Users/stephane.ma/Sites/instantsearch/dropdownfacets/favicon.png: Invalid Version: undefined
at new SemVer (/Users/stephane.ma/Sites/instantsearch/dropdownfacets/node_modules/@babel/preset-env/node_modules/semver/semver.js:314:11)
at compare (/Users/stephane.ma/Sites/instantsearch/dropdownfacets/node_modules/@babel/preset-env/node_modules/semver/semver.js:647:10)
at Function.lt (/Users/stephane.ma/Sites/instantsearch/dropdownfacets/node_modules/@babel/preset-env/node_modules/semver/semver.js:688:10)
at /Users/stephane.ma/Sites/instantsearch/dropdownfacets/node_modules/@babel/preset-env/lib/index.js:273:15
at Object.default (/Users/stephane.ma/Sites/instantsearch/dropdownfacets/node_modules/@babel/helper-plugin-utils/lib/index.js:23:12)
at getEnvPlugins (/Users/stephane.ma/Sites/instantsearch/dropdownfacets/node_modules/parcel-bundler/src/transforms/babel/env.js:62:34)
at getEnvConfig (/Users/stephane.ma/Sites/instantsearch/dropdownfacets/node_modules/parcel-bundler/src/transforms/babel/env.js:12:25)
at async getBabelConfig (/Users/stephane.ma/Sites/instantsearch/dropdownfacets/node_modules/parcel-bundler/src/transforms/babel/config.js:32:19)
at async babelTransform (/Users/stephane.ma/Sites/instantsearch/dropdownfacets/node_modules/parcel-bundler/src/transforms/babel/transform.js:6:16)
at async JSAsset.pretransform (/Users/stephane.ma/Sites/instantsearch/dropdownfacets/node_modules/parcel-bundler/src/assets/JSAsset.js:83:5)

Tahnk you for support,

Stephane

在 facet-dropdown 示例中执行 npm install，然后执行 npm start 以复现故障，接着检查 favicon.png 如何经由 Parcel 和 Babel 传递，并以报告的 @babel/preset-env semver 堆栈跟踪作为起点。示例能够在不出现 Invalid Version: undefined 错误的情况下成功启动，即表示完成。

由索引模型根据 Issue 内容生成。