parse_ts(ts) returns timezone-naive datetimes

Issue #170 duplicate
Bouke Haarsma
created an issue

When using django-storages + s3boto for storing statics, a lot of files are re-uploaded as they seem updated. However, there parse_ts ignores USE_TZ setting and returns datetime-naive last modification datetimes. Note the Z at the end of last_modified; it should be in UTC datetime. As my timezone differs from UTC, collectstatic assumes a lot of files changed.

last_modified = u'2013-05-08T07:59:41.000Z'