Kernel 4.20 rebase plans

The 4.20 kernel was released just before the end of the year, but the
first stable update should be dropping in the next day or two. We
have a 4.20 test day scheduled for Tuesday, January 15th. Depending
on the results of that test day, Fedora 29 will be rebased very
shortly afterwards, followed by F28 approximately a week later. Of
course the results of the test day could end up changing this, but it
is the current plan.