Publish react-datepicker sub-package in commonjs format (#1358)

* Publish react-datepicker sub-package as commonjs format

* changelog

.npmignore

@@ -7,6 +7,7 @@ generator-eui/
 test/
 src-docs/
 src-framer/
+packages/react-datepicker
 .nvmrc
 
 # typescript output

CHANGELOG.md

@@ -4,8 +4,14 @@
 - Altered `EuiHeader`'s location of `EuiHeaderBreadcrumbs` based on the new `truncate` ability ([#1346](https://github.com/elastic/eui/pull/1346))
 - Added support for `href` and `target` props in `EuiBasicTable` actions ([#1347](https://github.com/elastic/eui/pull/1347))
 
+**Bug fixes**
+
+- Fixed EUI when used in an environment lacking ES Modules support, e.g. Jest ([#1358](https://github.com/elastic/eui/pull/1358))
+
 ## [`5.4.0`](https://github.com/elastic/eui/tree/v5.4.0)
 
+**Note: this release broke usage of EUI in non-ES Module compatible environments. This is fixed in `5.5.0`.**
+
 - Added 3 new icons — `folderOpen`, `folderClosed`, and `crosshairs` ([#1350](https://github.com/elastic/eui/pull/1350))
 - Added `bottomGraphic` prop to `EuiCard` for Kibana home page ([#1338](https://github.com/elastic/eui/pull/1338))
 - Added keyboard and screenreader support to `EuiDatePicker` ([#1337](https://github.com/elastic/eui/pull/1337))

packages/index.js

@@ -1,3 +1,5 @@
-import ReactDatePicker from './react-datepicker';
+var ReactDatePicker = require('./react-datepicker').default;
 
-export { ReactDatePicker };
+module.exports = {
+  ReactDatePicker: ReactDatePicker
+};