Log Message:
(sysutils/R-later) Updated to 1.0.0

## later 1.0.0

* Added private event loops: these are event loops that can be run
  independently from the global event loop. These are useful when you
  have code that schedules callbacks with `later()`, and you want to
  call `run_now()` block and wait for those callbacks to execute
  before continuing. Without private event loops, if you call
  `run_now()` to wait until a particular callback has finished, you
  might inadvertantly run other callbacks that were scheduled by other
  code. With private event loops, you can create a private loop,
  schedule a callback on it, then call `run_now()` on that loop until
  it executes, all without interfering with the global
  loop. ([#84](https://github.com/r-lib/later/pull/84))