try make coveralls alive

package.json

@@ -4,7 +4,7 @@
   "description": "Opinionated XML generator and parser",
   "main": "index.js",
   "scripts": {
-    "test": "istanbul cover _mocha -- tests && cat ./coverage/lcov.info | coveralls.js"
+    "test": "istanbul cover _mocha -- tests && cat ./coverage/lcov.info | coveralls"
   },
   "repository": {
     "type": "git",