Merge pull request #9 from kaichen/master

为独立配置Uploader添加了文档
Add Benchmark on test.
改进 Upyun 初始化，将少连接的过程;
Update README.md
Update README.md
Merge pull request #14 from huacnlee/master

改进 Upyun 初始化，共享连接
0.1.6
Update lib/carrierwave/storage/upyun.rb

解决 “改进 Upyun 初始化，减少连接的过程” 中bucket混乱的问题
属于issue #16
Merge pull request #18 from vvdpzz/master

Fix issue 16 并减少连接
rework the connection sharing for fixing conflict bucket issue
Merge branch 'cache_connection'