promises 1.2.1

• future_promise() received a speed improvement when submitting many requests with a minimal number of {future} workers. If future_promise() runs out of available {future} workers, then future_promise() will preemptively return for the remainder of the current {later} execution. While it is possible for {future} to finish a job before submitting all of the future_promise() requests, the time saved by not asking {future}'s worker availability will be faster overall than if a few jobs were submitted early. (#78)

• Fixed #86: future_promise() spuriously reports unhandled errors. (#90)

• Move {fastmap} from Suggests to Imports for better {renv} discovery. (#87)