Add tests and update CMake to build them

Add comprehensive unit tests in tests/test_all.cpp

Refactor CMakeLists: set C++17 and CMAKE_CXX_STANDARD_REQUIRED,
introduce a SOURCES list used by executables, add a
deep_miner_tests target, and set cmake_minimum_required to 3.15

CMakeLists.txt

@@ -1,22 +1,26 @@
-cmake_minimum_required(VERSION 4.2)
+cmake_minimum_required(VERSION 3.15)
 project(deep_miner)
 
-set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 include_directories(include)
 
+set(SOURCES
+    src/BaseRobot.cpp
+    src/SortBot.cpp
+    src/World.cpp
+    src/DigDeepBot.cpp
+    src/Game.cpp
+    src/RandomBot.cpp
+)
+
 add_executable(deep_miner
-        include/BaseRobot.h
-        include/Robot.h
-        include/SortBot.h
-        include/World.h
-        src/BaseRobot.cpp
-        src/SortBot.cpp
-        src/World.cpp
-        include/Game.h
-        include/DigDeepBot.h
-        include/RandomBot.h
-        src/DigDeepBot.cpp
-        src/Game.cpp
-        src/RandomBot.cpp
-        main.cpp)
+    ${SOURCES}
+    main.cpp
+)
+
+add_executable(deep_miner_tests
+    ${SOURCES}
+    tests/test_all.cpp
+)