common: remove obsolete yesterday.py/sh (Python 2)

common/yesterday.py

-#!/usr/bin/python
-
-from datetime import date, timedelta
-
-yesterday = date.today() - timedelta(1)
-print yesterday.strftime('%Y%m%d')

common/yesterday.sh

-date -d yesterday  "+%Y%m%d"
\ No newline at end of file