Switched to gtest for unit testing

src/test/database/CMakeLists.txt

@@ -1,11 +1,15 @@
 
 add_executable(test-database
+	Artist.cpp
+	Cluster.cpp
 	DatabaseTest.cpp
+	Track.cpp
 	)
 
 target_link_libraries(test-database PRIVATE
 	lmsdatabase
+	GTest::GTest
 	)
 
-add_test(NAME database COMMAND test-database)
+gtest_discover_tests(test-database)