correct utcoffset return type

[samuelcolvin]

import datetime
tz = datetime.timezone(datetime.timedelta(seconds=3600))
dt = datetime.datetime(2016, 1, 1, tzinfo=tz)
print(repr(dt.utcoffset()))
#> datetime.timedelta(0, 3600)

same for datetime.time and python 2.7

[gvanrossum]

Thanks!