add travis.yaml
fix
Merge pull request #14 from rwifeng/b_rwf_travis

add travis yml
Merge pull request #19 from qiniu/develop

Release v3.2.3
v3.3.0
updated doc
Merge pull request #20 from why404/release/v3.3.0

v3.3.0
Merge pull request #21 from qiniu/master

Release 3.3.0