Add initial prototype.

3-mid/physics/implement/box2d/contrib/unit-test/CMakeLists.txt

@@ -0,0 +1,18 @@
+add_executable(unit_test
+    doctest.h
+    hello_world.cpp
+    collision_test.cpp
+    joint_test.cpp
+    math_test.cpp
+    world_test.cpp
+)
+
+set_target_properties(unit_test PROPERTIES
+	CXX_STANDARD 11
+    CXX_STANDARD_REQUIRED YES
+    CXX_EXTENSIONS NO
+)
+target_link_libraries(unit_test PUBLIC box2d)
+
+source_group(TREE ${CMAKE_CURRENT_SOURCE_DIR} FILES doctest.h
+    hello_world.cpp collision_test.cpp joint_test.cpp math_test.cpp world_test.cpp )