New raid feature and hero boosts

[Kerridoc]

Please read the release notes:

Version 20 Release Notes

Status (Friday, 22 Mar): We have now rolled out the update for both Android & iOS - please update your game! We are hoping to enable Raid Tournaments next week. New Raid Tournaments added. Raid Tournaments are special Raids that you can join each week. Raid Tournaments have 3 phases: Preparation Phase that lasts for 24 hours. During the preparation phase you join the up coming Tournament and prepare your defense team. You can only use defense teams that match the event rules. Battle Phase t…

There are specific threads for most changes.