Upgrade Kong version 2.7.x directly to 3.x

[hwlee96]

Would it be possible to upgrade Kong in DB-mode directly from 2.7.x to 3.x, without upgrading it to 2.8.2 first? Because the only difference in the migrations files between 2.8.x and 2.7.x is this script for the creation of vaults_beta table to provide secrets management but we are not using that feature at all.

[chronolaw]

I think it is possible, but we must test it before we deploy it in the production environment.