fix: 修复windows环境运行等问题 close #38 (#39)

* 1. 修复windows环境支持问题；

2. 由webpack插件清空dist目录，优化执行脚本；

* clean-webpack-plugins移除

example/ssr-with-js/package.json

@@ -16,13 +16,13 @@
   },
   "scripts": {
     "debug": "egg-bin debug",
-    "start": "concurrently \"npm run ssr\" \" npm run csr \"",
-    "ssr": "rm -rf dist && concurrently \"egg-bin dev\" \"NODE_ENV=development webpack --watch --config ./build/webpack.config.server.js\"",
-    "csr": "NODE_ENV=development webpack-dev-server --port 8000 --hot --client-log-level error --config ./build/webpack.config.client.js",
+    "start": "rm -rf dist && concurrently \"npm run ssr\" \" npm run csr \"",
+    "ssr": "concurrently \"egg-bin dev\" \"cross-env NODE_ENV=development webpack --watch --config ./build/webpack.config.server.js\"",
+    "csr": "cross-env NODE_ENV=development webpack-dev-server --port 8000 --hot --client-log-level error --config ./build/webpack.config.client.js",
     "prod": "npm run build && eggctl start",
-    "build:server": "NODE_ENV=production webpack --config build/webpack.config.server.js",
-    "build": "rm -rf dist && NODE_ENV=production webpack --config build/webpack.config.client.js && npm run build:server",
-    "analyze": "NODE_ENV=production npm_config_report=true npm run build"
+    "build:server": "cross-env NODE_ENV=production webpack --config build/webpack.config.server.js",
+    "build": "cross-env NODE_ENV=production webpack --config build/webpack.config.client.js && npm run build:server",
+    "analyze": "cross-env NODE_ENV=production npm_config_report=true npm run build"
   },
   "browserslist": [
     ">0.2%",
@@ -43,6 +43,7 @@
     "browserslist": "^4.6.3",
     "caniuse-lite": "1.0.30000974",
     "concurrently": "^4.1.0",
+    "cross-env": "^5.2.0",
     "css-hot-loader": "^1.4.3",
     "css-loader": "1.0.0",
     "css-modules-require-hook": "^4.2.3",