Revert "Update nix-tools version (#174)"

This reverts commit cd810e5.

The stack-to-nix flags generation is not correct yet.

Author: rvl

changelog.md

@@ -1,12 +1,8 @@
 This file contains a summary of changes to Haskell.nix and `nix-tools`
 that will impact users.
 
-## June 12, 2019
-  * Updated [nix-tools][]. This fixes subdirs on source repos with
-    `cabal.project` and adds support for `stack.yaml` flags.
-
 ## June 7, 2019
-  * Several additions to the [documentation][].
+  * Several additions to the [documentation](https://input-output-hk.github.io/haskell.nix/).
     * More information about getting nix-tools, Haskell.nix, pinning.
     * Updates the stack-to-nix and cabal-to-nix guides.
     * Adds a section on development environments.
@@ -49,6 +45,3 @@ that will impact users.
     expose `extras` instead of `overlay`. Similarly `mkStackPkgSet`, `mkPkgSet` and `mkCabalProjectPkgSet`
     take a `pkg-def-extras` instead of `pkg-def-overlay` argument.  If you are using `iohk-nix`, the
     `iohk-overlay` was parameter was renamed to `iohk-extras`.
-
-[documentation]: https://input-output-hk.github.io/haskell.nix/
-[nix-tools]: https://github.com/input-output-hk/nix-tools

nix-tools/nix-tools-src.json

@@ -1,7 +1,7 @@
 {
   "url": "https://github.com/input-output-hk/nix-tools",
-  "rev": "bb5700d04f0ff2d1a3a7b3278121c1ec67898793",
-  "date": "2019-06-10T17:10:00+08:00",
-  "sha256": "11q34s5hm76vb6r01h3r5ya9k9f4xqz2xdf958frhn6jb3jjihf6",
+  "rev": "69ca9bd0c1994f7bddb12bc1a99ac980e7365c14",
+  "date": "2019-05-23T11:35:17+08:00",
+  "sha256": "0f9ds6i4qni6xfgh8bq5kr469wr8j7a2zlb9l9g6gqy0y3hpihqm",
   "fetchSubmodules": false
 }