bump version to 2.5.2

Merge pull request upyun#51 from yejingx/master

rename

version 2.5.0

version 2.4.2

Merge pull request upyun#44 from huangnauh/fix_md5

fix-resume-md5

bump version to 2.4.0 [skip ci]

bump version to v2.3.2 [skip ci]

bump version to v2.3.1 [skip ci]

add install_requires [skip ci]

Merge pull request upyun#15 from januszry/patch-1

read_timeout can be set individually