Wrong dates for "winter" if year is provided

[adrienball]

Forwarding the issue snipsco/snips-nlu#833.

Hi,

Depending on how a question is asked, the timeframe identified for winter varies:

• "in winter":

"value": {
        "from": "2019-12-21 00:00:00 +01:00",
        "kind": "TimeInterval",
        "to": "2020-03-21 00:00:00 +01:00"
}

• "in winter 2019" (dates in 2020 are removed)

"value": {
        "from": "2019-12-21 00:00:00 +01:00",
        "kind": "TimeInterval",
        "to": "2020-01-01 00:00:00 +01:00"
}

Best,
Joffrey