Add namespace to docker image name

Add instructions for running the bot under Docker

Add docker build

Remove unnecessary indirection

Factor Timer creation out of mainline code

Remove all references to syncFile

Save matrix sync state in the sqlite database

Source organization cleanup

Factor out scheduling reminders

Cleanup afforded by abstracting the model

Factor out DB access into model file

Flesh out readme

Ignore timer database

Add timer persistence

Rename default sync state file to `sync.json`