move contrib examples to a dedicated contrib directory

examples/python/CMakeLists.txt

@@ -1,24 +0,0 @@
-if (NOT BUILD_PYTHON)
-  return()
-endif()
-
-foreach(TEST
-		hidato_table
-		integer_programming
-		knapsack
-		linear_programming
-		pyflow_example
-		tsp
-		vrp
-		vrpgs
-		cvrp
-		cvrptw
-		)
-	add_test(py${TEST}_venv ${VENV_BIN_DIR}/python ${CMAKE_CURRENT_SOURCE_DIR}/${TEST}.py)
-	set_tests_properties(py${TEST}_venv PROPERTIES DEPENDS build_venv)
-endforeach()
-
-include(GNUInstallDirs)
-install(DIRECTORY .
-	DESTINATION ${CMAKE_INSTALL_DATADIR}/ortools/examples/python
-	FILES_MATCHING PATTERN "*.py")