Update TODO's.

TODO.md

@@ -1,9 +1,12 @@
 TODO
 ====
 
+* Create an argument parser that lets one specify which argparse to
+  test, as well as running an individual test.
+* Add a test for the new subparser functionality.
 * Expose a way to customize the help header for a particular action:
   http://stackoverflow.com/questions/9234258/in-python-argparse-is-it-possible-to-have-paired-no-something-something-arg
-* Get docs working with Sphinx.
+* Get original argparse docs building with Sphinx.
 * Fix up long description.
 * DRY up the indenting used in the first and second passes.
   - Include subcommand groups in the determination of `_compute_max_action_length()`.