gtest: Use native cmake/ninja builder

Clean up the expression and add pkgconfig support

pkgs/development/libraries/gtest/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, cmake, fetchFromGitHub }:
+{ stdenv, cmake, ninja, fetchFromGitHub }:
 stdenv.mkDerivation rec {
   name = "gtest-${version}";
   version = "1.8.1";
@@ -10,24 +10,7 @@ stdenv.mkDerivation rec {
     sha256 = "0270msj6n7mggh4xqqjp54kswbl7mkcc8px1p5dqdpmw5ngh9fzk";
   };
 
-  buildInputs = [ cmake ];
+  nativeBuildInputs = [ cmake ninja ];
-
-  configurePhase = ''
-    mkdir build
-    cd build
-    cmake ../ -DCMAKE_INSTALL_PREFIX=$out
-  '';
-
-  installPhase = ''
-    mkdir -p $out/lib
-    cp -v googlemock/gtest/libgtest.a googlemock/gtest/libgtest_main.a googlemock/libgmock.a googlemock/libgmock_main.a $out/lib
-    ln -s $out/lib/libgmock.a $out/lib/libgoogletest.a
-    mkdir -p $out/include
-    cp -v -r ../googlemock/include/gmock $out/include
-    cp -v -r ../googletest/include/gtest $out/include
-    mkdir -p $out/src
-    cp -v -r ../googlemock/src/* ../googletest/src/* $out/src
-  '';
 
   meta = with stdenv.lib; {
     description = "Google's framework for writing C++ tests";