refactoring: test_minimum_for_5_and_9 rename

src/test/test_funktionen.c

@@ -74,7 +74,7 @@ void test_maximum(void) {
     TEST_ASSERT_FLOAT_WITHIN(0.000001, 9.0, result);
 }
 
-void test_minimum(void) {
+void test_minimum_for_5_and_9(void) {
     float result = minimum(5.0, 9.0);
     TEST_ASSERT_FLOAT_WITHIN(0.000001, 5.0, result);
 }