Merge pull request #4 from qiniu/develop

first commit
Merge pull request #9 from qiniu/develop

Release v6.0.0
Merge pull request #10 from qiniu/develop

Release v6.0.1
Merge pull request #20 from qiniu/develop

Release v6.0.2
Merge pull request #22 from qiniu/develop

Release v6.1.0
Merge pull request #24 from qiniu/develop

Release v6.1.1
Merge pull request #25 from qiniu/develop

Update CHANGELOG.md
Merge pull request #31 from qiniu/develop

merge develop to master
Merge pull request #34 from qiniu/develop

fix sample codes in doc
Merge pull request #40 from qiniu/develop

Release v6.1.2
Merge pull request #44 from qiniu/develop

add warning of utf8 keys
Merge pull request #46 from qiniu/develop

modify download domain
Merge pull request #50 from qiniu/develop

Release 6.1.3
Merge pull request #52 from qiniu/develop

Release v6.1.4
Merge pull request #59 from qiniu/develop

Release v6.1.5
Merge pull request #63 from qiniu/develop

v6.1.6
Merge pull request #65 from qiniu/develop

Release v6.1.7
Merge pull request #68 from qiniu/develop

Release 6.1.8
Merge pull request #75 from qiniu/develop

Release 6.1.9
Merge pull request #80 from qiniu/develop

Release 6.1.10