message: Prepare changelog for v1.1.2
diff: +Changes in [1.1.2](https://github.com/matrix-org/matrix-react-sdk/releases/tag/v1.1.2) (2019-05-15)
  +===================================================================================================
  +[Full Changelog](https://github.com/matrix-org/matrix-react-sdk/compare/v1.1.1...v1.1.2)
  +
  + * Always thumbnail for GIFs
  + [\#2976](https://github.com/matrix-org/matrix-react-sdk/pull/2976)
  + * Fix Single Sign-on
  + [\#2975](https://github.com/matrix-org/matrix-react-sdk/pull/2975)
  +
  Changes in [1.1.1](https://github.com/matrix-org/matrix-react-sdk/releases/tag/v1.1.1) (2019-05-14)
  ===================================================================================================
  [Full Changelog](https://github.com/matrix-org/matrix-react-sdk/compare/v1.1.0...v1.1.1)
  