remove babel polyfill (#2139)

package.json

@@ -24,7 +24,6 @@
   },
   "dependencies": {
     "@antv/data-set": "^0.9.0",
-    "@babel/polyfill": "^7.0.0",
     "@babel/runtime": "^7.0.0",
     "antd": "^3.9.1",
     "bizcharts": "^3.1.10",
@@ -53,8 +52,8 @@
     "react-router-dom": "^4.3.1"
   },
   "devDependencies": {
-    "umi": "^2.0.0",
-    "umi-plugin-react": "^1.0.0",
+    "umi": "^2.0.1",
+    "umi-plugin-react": "^1.0.1",
     "@types/react": "^16.4.11",
     "@types/react-dom": "^16.0.6",
     "antd-pro-merge-less": "^0.0.9",

src/global.js

-import '@babel/polyfill';