chore: Try gif format instead of gifv

Author: emyann

README.md

@@ -11,7 +11,7 @@
 - [x] [Webpack Dashboard](https://github.com/FormidableLabs/webpack-dashboard)
 - [x] [Karma](https://karma-runner.github.io/1.0/index.html), [Jasmine](https://jasmine.github.io/)
 
-![Imgur](https://i.imgur.com/sj1kwB9.gifv)
+![Imgur](https://i.imgur.com/sj1kwB9.gif)
 
 ## Quick Overview