optimize bundle size and resize/sharp image upload

fix #11

client/babel.config.js

@@ -1,5 +1,14 @@
 module.exports = {
   presets: [
-    '@vue/app'
+    '@vue/app' //, 'es2015', { 'modules': false }
+  ],
+  plugins: [
+    [
+      'component',
+      {
+        'libraryName': 'element-ui',
+        'styleLibraryName': 'theme-chalk'
+      }
+    ]
   ]
 }