add platforms option with unicorn gem, because unicorn can't install in windows
use html-pipeline since dependencies on charlock has been removed

refs #264
Merge pull request #264 from ywjno/master

add platforms option with unicorn gem
Merge pull request #265 from doitian/switch-back-to-html-pipeline

use html-pipeline since dependencies on charlock has been removed
change gem source to taobao
merge.
Merge remote-tracking branch 'upstream/master'