Fix samples build with make and separate build dir

Author: wravery

samples/CMakeLists.txt

@@ -3,6 +3,8 @@
 
 cmake_minimum_required(VERSION 3.8.2)
 
+file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/unified)
+
 # todaygraphql
 add_custom_command(
   OUTPUT
@@ -18,6 +20,8 @@ add_custom_command(
 file(STRINGS separate/today_schema_files SEPARATE_SCHEMA_CPP)
 list(TRANSFORM SEPARATE_SCHEMA_CPP PREPEND separate/)
 
+file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/separate)
+
 add_custom_command(
   OUTPUT
     separate/today_schema_files