Update Dockerfile

Dockerfile

@@ -8,7 +8,7 @@ COPY . .
 RUN npm install cnpm -g --no-progress --registry=httpsregistry.npm.taobao.org
 RUN cnpm install --no-progress
 # 构建
-RUN npm run build
+RUN npm run build:staging
 # production stage
 # 使用nginx镜像
 FROM nginx:stable-alpine as production-stage