docs(readme): add browserstack attribution

README.md

@@ -177,6 +177,10 @@ The final `type='img'` component will be created with the options passed into th
 
 We support the latest version of Google Chrome (which [automatically updates](https://support.google.com/chrome/answer/95414) whenever it detects that a new version of the browser is available). We also support the current and previous major releases of desktop Firefox, Internet Explorer, and Safari on a rolling basis. Mobile support is tested on the most recent minor version of the current and previous major release for the default browser on iOS and Android (e.g., iOS 9.2 and 8.4). Each time a new version is released, we begin supporting that version and stop supporting the third most recent version.
 
+This browser support is made possible by the great support from [BrowserStack](https://www.browserstack.com/).
+
+<img src="docs/images/Browserstack-logo@2x.png" width="300">
+
 ## Meta
 
 React-imgix was originally created by [Frederick Fogerty](http://twitter.com/fredfogerty). It's licensed under the ISC license (see the [license file](https://github.com/imgix/react-imgix/blob/master/LICENSE.md) for more info). Any contribution is absolutely welcome, but please review the [contribution guidelines](https://github.com/imgix/react-imgix/blob/master/CONTRIBUTING.md) before getting started.