Update Readme

Author: liderman

README.md

@@ -14,7 +14,12 @@ Usage
     // wordBase = "ваз"
 ```
 
+Requirements
+-----------
+
+* Need at least `go1.2` or newer.
+
 Documentation
 -----------
 
-You can read package documentation [here](http:godoc.org/github.com/liderman/rustemmer).
+You can read package documentation [here](http:godoc.org/github.com/liderman/rustemmer).