Makefile has target "test". Add reference output for test.

Makefile

@@ -5,6 +5,10 @@ MAIN = ccmeta
 
 all : $(MAIN)
 
+test : all .FORCE
+	./$(MAIN) < $(MAIN)-test.txt > $(MAIN)-test.out
+	diff $(MAIN)-test.ref $(MAIN)-test.out
+
 $(MAIN) : $(MAIN).c object.c buffer.h
 	$(CC) $(CFLAGS) -o $@ $@.c $(LDLIBS)
 
@@ -15,7 +19,7 @@ $(MAIN) : $(MAIN).c object.c buffer.h
 	mv $@.new $@
 
 tidy : .FORCE
-	rm -f *~
+	rm -f *~ $(MAIN)-test.out
 
 clean : .FORCE
 	rm -f $(MAIN) $(MAIN).c