Gitlab notifications on Mattermost have incorrect date/time for closed issues.

[aditya-konarde]

The notifications show an incorrect date/time in the message:

Issue #718 closed by xyz in repository on 2017-10-31 12:00:07 UTC

Here the timestamp is actually incorrect, as the issue was actually closed on Nov 2 2017.

Probably integration always reports date of issue creation: https://github.com/NotSqrt/mattermost-integration-gitlab/blob/master/mattermost_gitlab/event_formatter.py#L126