Leaderboard score items expiration date timezone is wrong

[potomak]

Leaderboard score items don't expire according to users' timezones.

Example daily score item:

{ _id: ObjectId("5897e27a814334000672964f"), uid: ObjectId("4e2d3ec0ad7f170001000001"), s: NumberLong("1"), eat: ISODate("2017-02-06T23:59:59.999Z") }

This is a my today's score item. The expiration date is set at tomorrow's end of day even if in my timezone, America/New York, is still 02/05.

The issue is that IncrementScore#to_user_timezone chances a UTC time's timezone instead of computing the correct local time according to user's timezone.