Merge pull request #31 from qiniu/develop

Release v6.0.0
Merge pull request #39 from qiniu/develop

for docs.qiniu.com release 6.1.2
Merge pull request #41 from qiniu/develop

Replace text picture with real picture
Merge pull request #45 from qiniu/develop

fix lost tag in put & add some sample to image process
Merge pull request #47 from qiniu/develop

Release 6.1.3
Merge pull request #51 from qiniu/develop

Release 6.1.4
Add token antileech doc
Merge pull request #59 from ikbear/token-antileech

Token antileech