Refactor WRT sqlalchemy introduces support for asyncio for Core and ORM?

[gvbgduh]

@tomchristie big news (if news)! sqlalchemy has now async engine that supports asyncio for Core and ORM, also it finally supports asyncpg as the driver.
While it's still considered to be an alpha, it's a huge step forward. It can also solve several classes of problems databases has. Like:

• dependency on psycopg2 for alembic or initial DB DDL
• subtle syntax differences in generated SQL that we observed (psycopg vs asyncpg)
• ORM support
• tighter migration and more unified usage of drivers (yet to be clarified how many async drivers are supported),
  some other.

It seems to be quite a big change, so I am wondering if there any strategy or view around that. With async API maturing in sqlalchemy it might worth considering adapting databases either into tighter integration with sqlalchemy or decoupling sqlalchemy at all providing a thin API on top of raw drivers (in case bringing databases with sqlalchemy might seem redundant).