nix file does not belong in root dir

taler-exchange-dev.nix

@@ -1,61 +0,0 @@
-{ stdenv, makeWrapper, pkgconfig, autoconf, automake, libtool, ccache, ccache_dir ? ""
-, gnunet-dev, postgresql, jansson, libgcrypt, libgnurl, libmicrohttpd }:
-
-stdenv.mkDerivation rec {
-  src = ./.;
-  name = "taler-exchange-dev";
-
-  buildInputs = [
-    makeWrapper pkgconfig autoconf automake libtool ccache
-    gnunet-dev postgresql jansson libgcrypt libgnurl libmicrohttpd
-  ];
-
-  patchPhase = ''
-    if [ -e Makefile ]; then
-      make distclean
-    fi
-  '';
-
-  NIX_CFLAGS_COMPILE = "-ggdb -O0";
-
-  configureFlags = [
-    "--enable-gcc-hardening"
-    "--enable-linker-hardening"
-
-    "--enable-logging=verbose"
-    "--enable-poisoning"
-  ];
-
-  preConfigure = ''
-    ./bootstrap
-
-    if [ -n "${ccache_dir}" ]; then
-      export CC='ccache gcc'
-      export CCACHE_COMPRESS=1
-      export CCACHE_DIR="${ccache_dir}"
-      export CCACHE_UMASK=007
-    fi
-  '';
-
-  doCheck = false;
-
-  postInstall = ''
-    # Tests can be run this way
-    #export GNUNET_PREFIX="$out"
-    #export PATH="$out/bin:$PATH"
-    #make -k check
-  '';
-
-  meta = with stdenv.lib; {
-    description = "Exchange for GNU Taler";
-
-    longDescription = ''
-    '';
-
-    homepage = https://taler.net/;
-
-    license = licenses.gpl3Plus;
-    platforms = platforms.gnu;
-    maintainers = with maintainers; [ ];
-  };
-}