Remove the confusing statement (#86)

Author: f3ath

README.md

@@ -1,7 +1,5 @@
 # [JSON API](http://jsonapi.org) spec implemented in PHP 7. Immutable
 
-**This is v2 of the implementation. For v1 click [here](https://github.com/json-api-php/json-api/tree/v1).**
-
 The goal of this library is to ensure strict validity of JSON API documents being produced.
 
 JSON: