Document example codes error

[Simin Jie]

In http://pytz.sourceforge.net/#problems-with-localtime, the codes are
>>> loc_dt = datetime(2002, 10, 27, 1, 30, 00)
>>> est_dt = eastern.localize(loc_dt, is_dst=True)
>>> edt_dt = eastern.localize(loc_dt, is_dst=False)
>>> print(est_dt.strftime(fmt) + ' / ' + edt_dt.strftime(fmt))
2002-10-27 01:30:00 EDT-0400 / 2002-10-27 01:30:00 EST-0500

But I think the names of the varibles are wrong. The `est_dt` should be named `edt_dt` and `edt_dt` should be named `est_dt`.