no cp39 wheels on pypi #691

• asyncpg version: latest
• Python version: 3.9
• Platform: win64
• Did you install asyncpg with pip?: yes - error on windows without C compiler

There's no cp39 wheels on pypi so it's not possible to automatically install asyncpg on windows64 with python 3.9.

Side note - the latest wheels on pypi are from august 2020 as for now - it could be major problem, because new pip installs packages from wheels, if they exists (and they exists but looks somehow obsolete - could be wrong though).