message: [changelog] 1.3.1
diff: ## Changelog
  +### [1.3.1](https://github.com/youzan/vant/tree/v1.3.1)
  +`2018-09-07`
  +
  +**Improvements**
  +
  +- Document: add vue-cli 3 guide [\#1754](https://github.com/youzan/vant/pull/1754)
  +
  +**Bug Fixes**
  +
  +- fix Button loading color [\#1768](https://github.com/youzan/vant/pull/1768)
  +- fix ImagePreview type definition [\#1767](https://github.com/youzan/vant/pull/1767)
  +- fix Tab color not work in card type [\#1763](https://github.com/youzan/vant/pull/1763)
  +- fix lib dir babel runtime module [\#1753](https://github.com/youzan/vant/pull/1753)
  +
  +
  ### [1.3.0](https://github.com/youzan/vant/tree/v1.3.0)
  `2018-08-31`
  