Add pack rule to Makefile

This creates an archive to be submitted via VMChecker.

Signed-off-by: Razvan Deaconescu <razvan.deaconescu@upb.ro>

src/Makefile

@@ -15,6 +15,11 @@ all: $(TARGET)
 $(TARGET): $(OBJS)
 	$(CC) ${LDFLAGS} -o $@ $^
 
+pack: clean
+	-rm -f ../src.zip
+	zip -r ../src.zip *
+
 clean:
+	-rm -f ../src.zip
 	-rm -f $(TARGET)
 	-rm -f $(OBJS)