依赖更新 && 构建调整 (#60)

* upgrade dependencies

* 更改所有 saladcss 写法

* fix: 升级依赖导致的样式错误

* fix: build vant css

* use es module when pack && webpack scope hoisting

* fix: vue module version

* delete unused npm script

* fix: build:vant script not work

* fix: webpack config format

* fix: build minify vant.js

* fix: captain ui relative link

postcss.config.js

@@ -0,0 +1,11 @@
+module.exports = {
+  plugins: [
+    require("postcss-easy-import")({
+      extensions: ['pcss', 'css']
+    }),
+    require("precss")(),
+    require("autoprefixer")({
+      browsers: ["Android >= 4.0", "iOS >= 7"]
+    })
+  ]
+};