gradle编译命令 & 自动打包等
./gradlew -v 版本号，首次运行，没有gradle的要下载的哦。
./gradlew clean 删除HelloWord/app目录下的build文件夹
./gradlew build 检查依赖并编译打包
./gradlew assembleDebug 编译并打Debug包
./gradlew assembleRelease 编译并打Release的包
./gradlew installRelease Release模式打包并安装
./gradlew uninstallRelease 卸载Release模式包
