Remove things we've done in `TODO` file.
MODIFY
TODO
TODO
@@ -2,8 +2,6 @@ Things to do (Things that are not done yet)
* special variables ($1,$2..)
* super in aliased methods
-* multi-assignment decomposing
-* keyword arguments in def statement
Things to improve (Done but things to fix)

Remove things we've done in `TODO` file.