remove unnecessary rollup plugins

Author: yyx990803

build/rollup.config.js

@@ -2,23 +2,14 @@ const buble = require('rollup-plugin-buble')
 const flow = require('rollup-plugin-flow')
 const cjs = require('rollup-plugin-commonjs')
 const node = require('rollup-plugin-node-resolve')
-const replace = require('rollup-plugin-replace')
 const version = process.env.VERSION || require('../package.json').version
 
 module.exports = {
   entry: 'src/index.js',
   dest: 'dist/vue-router.js',
   format: 'umd',
   moduleName: 'VueRouter',
-  plugins: [
-    flow(),
-    replace({
-      'process.env.NODE_ENV': JSON.stringify(process.env.NODE_ENV)
-    }),
-    node(),
-    cjs(),
-    buble()
-  ],
+  plugins: [flow(), node(), cjs(), buble()],
   banner:
 `/**
  * vue-router v${version}

package.json

@@ -48,12 +48,10 @@
     "path-to-regexp": "^1.5.3",
     "phantomjs-prebuilt": "^2.1.7",
     "rollup": "^0.33.0",
-    "rollup-plugin-babel": "^2.6.1",
     "rollup-plugin-buble": "^0.12.1",
     "rollup-plugin-commonjs": "^3.1.0",
     "rollup-plugin-flow": "^1.0.0",
     "rollup-plugin-node-resolve": "^1.7.1",
-    "rollup-plugin-replace": "^1.1.1",
     "rollup-watch": "^2.4.0",
     "selenium-server": "^2.53.1",
     "uglify-js": "^2.7.0",