Add an IE11 compatible version of wrapper to distribution

Author: ChristianMurphy

Diff for: .babelrc

@@ -0,0 +1,16 @@
+{
+  "plugins": [
+    "babel-plugin-transform-custom-element-classes"
+  ],
+  "presets": [
+    [
+      "@babel/preset-env",
+      {
+        "modules": false,
+        "targets": {
+          "ie": "11"
+        }
+      }
+    ]
+  ]
+}

Diff for: package.json

@@ -28,13 +28,17 @@
   },
   "homepage": "https://github.com/vuejs/web-component-wrapper#readme",
   "devDependencies": {
+    "@babel/core": "^7.0.0",
+    "@babel/preset-env": "^7.0.0",
+    "babel-plugin-transform-custom-element-classes": "^0.1.0",
     "eslint": "^4.16.0",
     "eslint-plugin-vue-libs": "^2.1.0",
     "http-server": "^0.11.1",
     "jest": "^22.1.4",
     "lint-staged": "^6.1.0",
     "puppeteer": "^1.0.0",
-    "rollup": "^0.55.3",
+    "rollup": "^0.65.2",
+    "rollup-plugin-babel": "^4.0.3",
     "vue": "^2.5.13",
     "yorkie": "^1.0.3"
   },

Diff for: rollup.config.js

@@ -1,3 +1,5 @@
+import babel from 'rollup-plugin-babel'
+
 export default {
   input: 'src/index.js',
   output: [
@@ -9,6 +11,14 @@ export default {
       format: 'iife',
       name: 'wrapVueWebComponent',
       file: 'dist/vue-wc-wrapper.global.js'
+    },
+    {
+      format: 'iife',
+      name: 'wrapVueWebComponent',
+      file: 'dist/vue-wc-wrapper.ie11.js',
+      plugins: [
+        babel()
+      ]
     }
   ]
 }