Changelog update.

Cabal/ChangeLog.md

-# 3.0.0.0 (current development version)
-  * TODO
+# 3.0.0.0 [Mikhail Glushenkov](mailto:mikhail.glushenkov@gmail.com) July 2019
   * Introduce set notation for `^>=` and `==` operators
     ([#5906](https://github.com/haskell/cabal/pull/5906)).
   * 'check' reports warnings for various ghc-\*-options fields separately

cabal-install/changelog

 -*-change-log-*-
 
-3.0.0.0 (current development version)
+3.0.0.0 Mikhail Glushenkov <mikhail.glushenkov@gmail.com> July 2019
 	* `v2-repl` no longer changes directory to a randomized temporary folder
 	  when used outside of a project. (#5544)
 	* `install-method` and `overwrite-policy` in `.cabal/config` now actually work. (#5942)