Add minimum backbone requirement to readme. Closes #53

Author: appleton

readme.md

@@ -5,6 +5,8 @@
 A Backbone plugin to cache calls to `Backbone.Model.prototype.fetch` and
 `Backbone.Collection.prototype.fetch` in memory and `localStorage`.
 
+Compatible with Backbone 1.0.0 and up.
+
 ## How it works
 This plugin intercepts calls to `fetch` and stores the results in a cache object (`Backbone.fetchCache._cache`). If fetch is called with `{ cache: true }` in the options and the URL has already been cached the AJAX call will be skipped.