Merge pull request #5 from qiniu/master

update docs
fix
remove secretkey
remove some code
Merge pull request #8 from wangjinlei/feature/fix_httpclient

Feature/fix httpclient
add
Merge pull request #10 from wangjinlei/feature/add_changelog_fix_legacy

add
Update CHANGELOG.md
Merge pull request #9 from qiniu/develop

Release v1.3.0