Feature Request: `run_weekly()` method

[sriramsv]

Currently, there is no easy way to execute code on a given day of the week, either we have to have a run_daily call which checks the self.date().isoweekday() to be a certain. This is unnecessary if we have a run_weekly() method which will execute at a given time on that day of week.

[dlashua]

Until this feature request is decided upon, you can use this:

self.run_daily(blah, blah, blah, constrain_days="wed")

[acockburn]

Sure, we can add this at some point.