message: Prepare changelog for v0.12.7-rc.1
diff: +Changes in [0.12.7-rc.1](https://github.com/matrix-org/matrix-react-sdk/releases/tag/v0.12.7-rc.1) (2018-06-06)
  +===============================================================================================================
  +[Full Changelog](https://github.com/matrix-org/matrix-react-sdk/compare/v0.12.6...v0.12.7-rc.1)
  +
  + * Update from Weblate.
  + [\#1944](https://github.com/matrix-org/matrix-react-sdk/pull/1944)
  + * Import react as React in src/components/views/elements/DNDTagTile.js
  + [\#1943](https://github.com/matrix-org/matrix-react-sdk/pull/1943)
  + * Fix click on faded left/right/middle panel -> close settings
  + [\#1940](https://github.com/matrix-org/matrix-react-sdk/pull/1940)
  + * Add null-guard to support browsers that don't support performance
  + [\#1942](https://github.com/matrix-org/matrix-react-sdk/pull/1942)
  + * Support third party integration managers in AppPermission
  + [\#1455](https://github.com/matrix-org/matrix-react-sdk/pull/1455)
  + * Update pinned messages in real time
  + [\#1934](https://github.com/matrix-org/matrix-react-sdk/pull/1934)
  + * Expose at-room power level setting
  + [\#1938](https://github.com/matrix-org/matrix-react-sdk/pull/1938)
  +
  Changes in [0.12.6](https://github.com/matrix-org/matrix-react-sdk/releases/tag/v0.12.6) (2018-05-25)
  =====================================================================================================
  [Full Changelog](https://github.com/matrix-org/matrix-react-sdk/compare/v0.12.6-rc.1...v0.12.6)
  