Currently, taskotron-trigger is only capable of running on incoming fedmsg. There are 2 use cases that would at least benefit from an alternate input stream
* downtime on the trigger node (so that we can re-schedule any jobs missed)
* system testing/development (so that we can trigger jobs at will instead of making a change and waiting for the next build/update)

While there are more complicated use cases that this doesn't address, the simplest implementation I can think of would be to support rescheduling from a log file.

• make sure that the log file from taskotron-trigger contains enough data to reschedule jobs
• add a utility to read that log file and behave as if the messages were coming in

If using the existing fedmsg-hub logging functionality won't work, propose another method/format that will.