message: [changelog] 0.11.12
diff: ## Changelog
  +### [0.11.12](https://github.com/youzan/vant/tree/v0.11.12)
  +`2017-12-15`
  +
  +**Improvements**
  +- ContactCard: add 'editable' prop [\#435](https://github.com/youzan/vant/pull/435) [@chenjiahan](https://github.com/chenjiahan)
  +- Coupon: support i18n [\#431](https://github.com/youzan/vant/pull/431) [@chenjiahan](https://github.com/chenjiahan)
  +
  +**Bug Fixes**
  +- fix Popup preventScroll not work in some cases [\#429](https://github.com/youzan/vant/pull/429) [@Tinysymphony](https://github.com/Tinysymphony)
  +- fix Picker should prevent default touchmove [\#432](https://github.com/youzan/vant/pull/432) [@chenjiahan](https://github.com/chenjiahan)
  +- fix Picker bottom area not dragable [\#433](https://github.com/youzan/vant/pull/433) [@chenjiahan](https://github.com/chenjiahan)
  +- fix PullRefresh head display error [\#436](https://github.com/youzan/vant/pull/436) [@chenjiahan](https://github.com/chenjiahan)
  +
  +
  ### [0.11.11](https://github.com/youzan/vant/tree/v0.11.11)
  `2017-12-13`
  