shell/exercises/hearing: Replace 2012-04-uchichicago commit with 2012-02-trieste Replace the copy-paste bf93a25 (added data, 2012-03-20) from the Chicago boot camp with the earlier 3e24204 (Added Da for Shell example, 2012-01-30) from the Trieste boot camp [2]. [1]: https://github.com/thehackerwithin/UofCSCBC2012 [2]: https://github.com/thehackerwithin/PyTrieste