Don't force CXX_STANDARD for Google Test.

Fixes #393 .

Author: gchatelet

CMakeLists.txt

@@ -211,10 +211,6 @@ if(BUILD_TESTING)
   # found.
   enable_language(CXX)
 
-  set(CMAKE_CXX_STANDARD 14)
-  set(CMAKE_CXX_STANDARD_REQUIRED ON)
-  set(CMAKE_CXX_EXTENSIONS OFF) # prefer use of -std14 instead of -gnustd14
-
   if(NOT TARGET gtest OR NOT TARGET gmock_main)
     # Download and unpack googletest at configure time.
     configure_file(