Update README with 2.0 details

Author: chris-pook

README.md

@@ -64,7 +64,7 @@ add the latest stable version of `ometria/magento2` to your `composer.json` file
     //...
     "require": {
         //...
-        "ometria/magento2": "^1.4"
+        "ometria/magento2": "^2.0"
     },
     //...