improve the build script

package.json

     "build:chart": "yarn run clean:chart && webpack --config build/webpack.chart.conf --mode production --env.production",
     "dev:mapv": "yarn run clean:mapv && webpack --config build/webpack.mapv.conf --mode development",
     "build:mapv": "yarn run clean:mapv && webpack --config build/webpack.mapv.conf --mode production --env.production",
-    "clean": "yarn run clean:base && yarn run clean:core && yarn run clean:chart && yarn run clean:mapv",
+    "clean": "yarn run clean:base && yarn run clean:core && yarn run clean:chart && yarn run clean:mapv && yarn run clean:sdk",
     "clean:base": "rimraf packages/base/dist",
     "clean:core": "rimraf packages/core/dist",
     "clean:chart": "rimraf packages/chart/dist",
-    "clean:mapv": "rimraf packages/mapv/dist"
+    "clean:mapv": "rimraf packages/mapv/dist",
+    "clean:sdk": "rimraf packages/sdk/dist"
   },
   "devDependencies": {
     "@babel/core": "^7.4.0",

scripts/build.js

 
 shell.echo(chalk.green('build sdk start'))
 
-shell.rm('-rf', path.resolve(__dirname, '..', 'packages/sdk/dist/*'))
+let outoutDir = path.resolve(__dirname, '..', 'packages/sdk/dist')
+
+fse.ensureDirSync(outoutDir)
+
+fse.emptyDirSync(outoutDir)
 
 const pkgs = ['base', 'core', 'chart', 'mapv']
+
 const count = pkgs.length
 
-pkgs.forEach(async (item, index) => {
-  await fse.exists(
+pkgs.forEach((item, index) => {
+  fse.exists(
     path.resolve(__dirname, '..', `packages/${item}/dist`),
-    exists => {
+    async exists => {
       if (exists) {
-        shell.cp(
-          '-R',
-          path.resolve(__dirname, '..', `packages/${item}/dist/*`),
-          path.resolve(__dirname, '..', 'packages/sdk/dist')
+        fse.copySync(
+          path.resolve(__dirname, '..', `packages/${item}/dist`),
+          outoutDir
         )
         shell.echo(chalk.yellow(`copy ${item} success`))
         if (index === count - 1) {
-          shell.echo(chalk.green('build sdk end'))
-          shell.exit(0)
+          await shell.echo(chalk.green('build sdk end'))
         }
       } else {
         shell.echo(chalk.red(`no ${item} dist`))
         if (index === count - 1) {
           shell.echo(chalk.green('build sdk end'))
-          shell.exit(0)
         }
       }
     }