Fix tiny thread pool bug

v0.0.27

Update setup.py

Fix bug

Merge pull request #50 from dt3310321/s3

S3

v0.0.25

Update setup.py

Modify UploadFileRequest to set verify_sha1

v0.0.24

Update setup.py

Add delimiter for ListFolderRequest

Add delimiter for ListFolderRequest

Fix up Chinese filename download

v0.0.22

Update setup.py

Fix up download region from spg to sgp

Update setup.py

Fix region sgp

修正 slice_size 的问题

v0.0.20

Update CHANGES.rst

细化错误码

Merge pull request #31 from Liuchang0812/patch-1

Create cos_op.py

允许下载的时候传入自定义headers

使用方法：

request = DownloadFileReqeust('xxx', 'yyyy', headers={'Referer': 'https://www.google.com.hk/webhp', 'User-Agent': 'Mozilla/5.0'})