Removing comment about supporting old versions of node

Author: Jose Zamora

README.md

@@ -21,7 +21,7 @@ Before using this library, you must have:
 npm install sparkpost
 ```
 
-*Note: Node.js versions 0.10 and 0.12 are no longer supported. For versions < 4, please continue using [sparkpost v1.3.8](https://github.com/SparkPost/node-sparkpost/tree/1.3.8)*
+*Note: Node.js versions 0.10 and 0.12 are no longer supported.*
 
 ## Initialization
 **new SparkPost(apiKey[, options])** - Initialization