add core stable + fix badges

Author: giansalex

README.md

@@ -1,8 +1,8 @@
 # XCodes - Greenter
 
-[![Travis-CI](https://img.shields.io/travis/giansalex/greenter-ws.svg?label=build&branch=master&style=flat-square)](https://travis-ci.org/giansalex/greenter-ws)
-[![Coverage Status](https://img.shields.io/coveralls/giansalex/greenter-ws.svg?label=coveralls&style=flat-square&branch=master)](https://coveralls.io/github/giansalex/greenter-ws?branch=master)
-[![Codacy Badge](https://api.codacy.com/project/badge/Grade/64cabd82882a461dbf82bdeb6accbc13)](https://www.codacy.com/app/giansalex/greenter-ws?utm_source=github.com&utm_medium=referral&utm_content=giansalex/greenter-ws&utm_campaign=Badge_Grade)  
+[![Travis-CI](https://img.shields.io/travis/giansalex/greenter-xcodes.svg?branch=master&style=flat-square)](https://travis-ci.org/giansalex/greenter-xcodes)
+[![Coverage Status](https://img.shields.io/coveralls/giansalex/greenter-xcodes.svg?style=flat-square&branch=master)](https://coveralls.io/github/giansalex/greenter-xcodes?branch=master)
+[![Codacy Badge](https://api.codacy.com/project/badge/Grade/9833db8de44b42ff92669e892adb5e1f)](https://www.codacy.com/app/giansalex/greenter-xcodes?utm_source=github.com&utm_medium=referral&utm_content=giansalex/greenter-xcodes&utm_campaign=Badge_Grade)  
 Códigos de Error en Facturación Electrónica SUNAT.
 
 # Install

composer.json

@@ -13,7 +13,7 @@
     "type": "library",
     "require": {
 	    "php": ">=5.5.9",
-        "greenter/core": "dev-master"
+        "greenter/core": "^1.2"
     },
 	"require-dev": {
         "phpunit/phpunit": ">=4.8 < 6.0"