ExcelUtil 3.0.5发布，修复若干bug

1.修复导出int,float,double,Date 类型的字段，在读取时候发生异常的问题
2.新增表头，合并第一行为表头（和导出文件名称保持一致）
用法如下：

//浏览器中直接下载

//导出不带表头，文件名称用当前时间，年月日时分秒命名
@GetMapping(value = "/export")
public void testExport(HttpServletResponse response) throws Exception{
   List<PhoneModel> list = new ArrayList<>();
   PhoneModel model = null;
   for(int i=0;i<10;i++){
      model = new PhoneModel();
      model.setNum((i+1));
      model.setColor("金色"+i);
      model.setPhoneName("苹果"+i+"S");
      model.setPrice(i);
      model.setSj(new Date());
      list.add(model);
   }
   ExcelUtil.exportExcelOutputStream(response,list,PhoneModel.class);
}

//导出带表头，文件名称和表头保持一致
@GetMapping(value = "/exportHeader")
public void testExportHeader(HttpServletResponse response) throws Exception{
   List<PhoneModel> list = new ArrayList<>();
   PhoneModel model = null;
   for(int i=0;i<10;i++){
      model = new PhoneModel();
      model.setNum((i+1));
      model.setColor("金色"+i);
      model.setPhoneName("苹果"+i+"S");
      model.setPrice(i);
      model.setSj(new Date());
      list.add(model);
   }
   ExcelUtil.exportExcelOutputStream(response,list,PhoneModel.class,"这是表头也是文件名");
}

引入pom

<!-- https://mvnrepository.com/artifact/net.oschina.likaixuan/excelutil -->
<dependency>
    <groupId>net.oschina.likaixuan</groupId>
    <artifactId>excelutil</artifactId>
    <version>3.0.5</version>
</dependency>