Merge pull request qiniu#342 from songfei9315/master

fix

Merge pull request qiniu#338 from songfei9315/master

add sms_ch

7.2.4

prepare to publish v7.2.2

prepare to publish v7.2.1

add 7.2.0 release note

Merge pull request qiniu#293 from jemygraw/master

publish v7.1.9

Merge pull request qiniu#286 from jemygraw/master

reset the kirk api to the previous version

Merge pull request qiniu#285 from jemygraw/master

fix the http rft time format from timestamp using utc timezone

Merge pull request qiniu#284 from jemygraw/master

add keep_last_modifed to put_file to support some customers' needs