update build process

build/rollup.config.js

@@ -0,0 +1,22 @@
+import resolve from 'rollup-plugin-node-resolve'
+import vue from 'rollup-plugin-vue'
+import commonjs from 'rollup-plugin-commonjs'
+import babel from 'rollup-plugin-babel'
+
+export default {
+  input: 'build/entry.js',
+  output: {
+    format: 'umd',
+    file: 'dist/datav.map.js',
+    name: 'datav'
+  },
+  plugins: [
+    resolve(),
+    babel({
+      exclude: 'node_modules/**'
+    }),
+    commonjs(),
+    vue(),
+  ],
+  external: ['Vue']
+}