Delayer

[pauby]

#84 can be achieved if delay is introduced to package update (way of 'pending' status). If delay is set to 3 days, the new version can be checked on virus total on actual update.

This can happen as a plugin that runs aftereach update and records pending updates with the date first seen in a local file (or gist).

For this before/after plugins should be implemented (currently doable inside beforeEach scriprtblock.

The other useful purpose would be to delay update until specific event is met such as day of the week, existence of update of some other package, etc.

Issue migrated from majkinetor/au#94