[$] Shortening the Python release schedule

The Python release cycle has an 18-month cadence; a new major release (e.g.Python 3.7) ismade roughly on that schedule. But Aukasz Langa, who is the releasemanager for Python 3.8 and 3.9, would like to see things movemore quickly-perhaps on a yearly cadence. In the first session after lunchat the 2018 Python Language Summit, Langa wanted to discuss that idea.