modern cmake

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c06e271..56054cd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,12 +4,10 @@
 if (NOT EXISTS "${PROJECT_SOURCE_DIR}/includes")
     execute_process(COMMAND bash "-c" "(cd ${PROJECT_SOURCE_DIR} && ./fetch-includes.sh)")
 endif()
-
-include_directories ("${PROJECT_SOURCE_DIR}/src")
-include_directories ("${PROJECT_SOURCE_DIR}/includes/rapidjson/include")
-# add_subdirectory("includes/rapidjson")
+# message("PROJECT_SOURCE_DIR ${PROJECT_SOURCE_DIR}")
 
 add_executable(delaunator src/main.cpp)
+target_include_directories (delaunator PRIVATE "${PROJECT_SOURCE_DIR}/includes/rapidjson/include")
 
 set(CPACK_PROJECT_NAME ${PROJECT_NAME})
 set(CPACK_PROJECT_VERSION ${PROJECT_VERSION})