[ADD] add a skeleton of the group and refactor some test datas.

tests/CMakeLists.txt

@@ -12,6 +12,7 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 add_executable(raytracing_test 
     main_test.cpp
 
+    00_common_data.cpp
     01_tuples.cpp
     02_1_colors.cpp
     02_2_canvas.cpp
@@ -26,6 +27,7 @@ add_executable(raytracing_test
     11_reflection_refraction.cpp
     12_cubes.cpp
     13_cylinders.cpp
+    14_groups.cpp
 )
 
 include_directories("${CMAKE_SOURCE_DIR}/tests")