Planned updates for new timezone databases?

Hi,
It looks like it's been a little while since you have updated this library. Do you plan to continue updating/maintaining it?

I made an attempt at updating the eggert dependency in order to pull in the [2019c](https://github.com/eggert/tz/releases/tag/2019c) release, but unfortunately ran into some build failures when running `make`- specifically, the script seems to go into an infinite loop somewhere in [this function](https://github.com/bigeasy/timezone/blob/master/util/transitions.js#L322-L381), when it reaches Asia/Hong_Kong. If you're able to provide some guidance on what might need to be updated to make the build work, I may be able to take a crack at submitting a patch.
Thank you!