message: Prepare changelog for v1.0.7
diff: +Changes in [1.0.7](https://github.com/matrix-org/matrix-react-sdk/releases/tag/v1.0.7) (2019-04-08)
  +===================================================================================================
  +[Full Changelog](https://github.com/matrix-org/matrix-react-sdk/compare/v1.0.6...v1.0.7)
  +
  + * Hotfix: bump js-sdk to 1.0.4, see https://github.com/matrix-org/matrix-js-sdk/releases/tag/v1.0.4
  +
  Changes in [1.0.6](https://github.com/matrix-org/matrix-react-sdk/releases/tag/v1.0.6) (2019-04-01)
  ===================================================================================================
  [Full Changelog](https://github.com/matrix-org/matrix-react-sdk/compare/v1.0.6-rc.1...v1.0.6)
  