drop stage-2

.babelrc

@@ -1,10 +1,10 @@
 {
   "env": {
     "development": {
-      "presets": ["es2015", "stage-2"]
+      "presets": ["es2015"]
     },
     "production": {
-      "presets": ["es2015-rollup-vue", "stage-2"]
+      "presets": ["es2015-rollup-vue"]
     }
   }
 }

package.json

@@ -34,7 +34,6 @@
     "babel-loader": "^6.0.0",
     "babel-preset-es2015": "^6.0.0",
     "babel-preset-es2015-rollup-vue": "^1.0.0",
-    "babel-preset-stage-2": "^6.0.0",
     "casperjs": "^1.1.0",
     "eslint": "^2.7.0",
     "eslint-config-standard": "^5.1.0",