[Bug] smash.gg tournament import dates are often off by 1

[jiangtyd]

When importing a smash.gg tournament, especially from the west coast, the dates are often a day later than they appear in smash.gg. For example:

https://smash.gg/tournament/friday-night-turnip-67/events/melee-singles/brackets?filter=%7B%22phaseId%22%3A145272%7D is on Friday, 9/8/2017, but it was imported as 9/9.

I think this is because the way in which we determine dates of tournaments is flawed: we use the "start time" of the first set in the tournament, but I think this time is computed in UTC, and if a West Coast tournament starts in the late afternoon, this will register as the next day in UTC.

Possible solutions:

• Assign a time zone to each region.
• Assign a time zone to each tournament (defaulting to the region's time zone.)
• Read the date directly from smash.gg. (Won't work very will for multi-day multi-phase tournaments.)

Additionally, we may want to read the date for each match in a tournament for accuracy of set dates in multi-day tournaments?

[BrandonCookeDev]

There's an issue semi-related to this where if you decide to import a tournament in multiple, individual phases each phase counts as a separate tournament for the ranking criteria