Update sqlalchemy to support >=1.4

[collerek]

After databases merge their solution and stop blocking the update: encode/databases#299

[johnthagen]

Would the fact that sqlalchemy 1.4 has native async support bring any improvements?

[collerek]

Immediately - no - since all queries are run through encode/databases.

This issue is rather to not block bumping version of sqlalchemy if you use it in other then ormar places, and I need to adjust ormar as version >= 1.4 has some breaking changes even without async support.

But looking at how encode/databases is half-abandoned in the long run I will probably switch fully to sqlalchemy, but that is a bigger refactor and since async support is still in alpha version in sqlalchemy (I'm also not very fond of the async API but I need to dig deeper) I'm waiting to see how the situation will develop.

This has been merged into encode/databases for 0.5.0.

[collerek]

Added in 0.10.17 (#325)