Add dev dependencies badge

kgryte · kgryte · commit 6869904c1aef · 2016-04-05T23:34:53.000-07:00
diff --git a/README.md b/README.md
@@ -9,3 +9,6 @@
 
 [dependencies-image]: http://img.shields.io/david/stdlib-js/stdlib/develop.svg
 [dependencies-url]: https://david-dm.org/stdlib-js/stdlib/develop
+
+[dev-dependencies-image]: http://img.shields.io/david/dev/stdlib-js/stdlib/develop.svg
+[dev-dependencies-url]: https://david-dm.org/dev/stdlib-js/stdlib/develop
