Version bump of SQLAlchemy 1.4

[jsmolina]

Is your feature request related to a problem? Please describe.
SQLAlchemy was launched on March 2021

Describe the solution you'd like
Gino should be able to support 1.4 version of SQLAlchemy.

[dnikolayev]

Sorry, please don't get it as a push, just want to get know if there are plans about Alchemy 1.4+ support.

[Pentusha]

@dnikolayev #799

[dnikolayev]

Thanks, @Pentusha
Looks like a problem. @fantix is the only one Maintainer, right?