zstd: 0.5.0 -> 0.5.1

Changes:
- New: Optimal parsing => Very high compression modes, thanks to @inikep
- Changed: Dictionary builder integrated into libzstd and zstd cli
- Changed (!): zstd cli now uses "multiple input files" as default mode. See zstd -h.
- Fix: high compression modes for big-endian platforms (#123)
- New: zstd cli : -t | --test command

pkgs/tools/compression/zstd/default.nix

···
 
 stdenv.mkDerivation rec {
   name = "zstd-${version}";
-  version = "0.5.0";
+  version = "0.5.1";
 
   src = fetchFromGitHub {
-    sha256 = "18jwhvzj3kv8lpr6fgild7a574lsak93fc1z8nvhcdbc1b1n2dsj";
+    sha256 = "18mfrq5fqd7gkkqrgc32rlb98vw45rq1vsbrg44bprg3mv6ca3ls";
     rev = "v${version}";
     repo = "zstd";
     owner = "Cyan4973";