Remove width on gif.

Now that it shows both iOS and Android the width prop was making it too small.

Author: joshuapinter

README.md

@@ -8,7 +8,7 @@
 - [Questions?](#questions)
 
 ### Demo
-<a href="https://raw.githubusercontent.com/gitim/react-native-sortable-list/master/demo.gif"><img src="https://raw.githubusercontent.com/gitim/react-native-sortable-list/master/demo.gif" width="350"></a>
+<a href="https://raw.githubusercontent.com/gitim/react-native-sortable-list/master/demo.gif"><img src="https://raw.githubusercontent.com/gitim/react-native-sortable-list/master/demo.gif"></a>
 
 ### Installation
 ```bash
@@ -49,4 +49,4 @@ Called when the active row was released.
 Feel free to contact me via
 - [Twitter](https://twitter.com/_gitim)
 
-If you find a bug, please [submit an issue](https://github.com/gitim/react-native-sortable-list/issues/new)
+If you find a bug, please [submit an issue](https://github.com/gitim/react-native-sortable-list/issues/new)