Importing a file with universal includes all the contents of its sibling directories

Hello,

I'm running into an issue in my production builds. This is what I have in my bundle file.

```js
const CompanyEdit = universal(import('comps/Company/Edit'));
```

The production build of the system includes the contents of `__tests__` and `__generated__` folders.

```
public/__generated__-GetKey.chunk-647967baa76de181db7c.js
public/__generated__-GetKey.chunk-647967baa76de181db7c.js.map
public/__generated__-RegenKey.chunk-4f4202d851a015422d6d.js
public/__generated__-RegenKey.chunk-4f4202d851a015422d6d.js.map
public/__generated__-updateCompany.chunk-c3ad3a2c0a71b001bb29.js
public/__generated__-updateCompany.chunk-c3ad3a2c0a71b001bb29.js.map
public/__tests__-AccessKeyManager-test.chunk-bed6e34b29ee6fbd5d72.js
public/__tests__-AccessKeyManager-test.chunk-bed6e34b29ee6fbd5d72.js.map
public/__tests__-__snapshots__-AccessKeyManager-test-js-snap.chunk-07f6461ec4547a0878ef.js
public/__tests__-__snapshots__-AccessKeyManager-test-js-snap.chunk-07f6461ec4547a0878ef.js.map
```

I'm using version 4 of react-universal-loader with Webpack 4.39.2.