support for hostname config field

[mayel]

Hi, this lib looks really interesting, thanks!
Here's a PR for a couples issues I encountered when trying it out.

[Schultzer]

Hey @mayel thanks for this PR, I’m properly not going to merge this as is, as I’m getting ready to commit a bigger refactor of the the pool that addresses the not readiness.

Regardless we do need to address the hostname.

[mayel]

Sounds good! I'll wait for your refactor before proceeding with it then :)

[Schultzer]

Sounds good! I'll wait for your refactor before proceeding with it then :)

Awesome, I just comitted what I've been working on. You might be hitting some subtle bugs that I'm still working on but you should be able to rebase your PR and adjust your changes.

[mayel]

I've re-applied the hostname fix, but wasn't properly able to test as compiling :sql as a dependency now fails intermittently with SQL.Application.start/2 is undefined in queries.ex, maybe because use SQL runs ensure_all_started(:sql) at compile time and the compiler enters a race condition?

[Schultzer]

I've re-applied the hostname fix, but wasn't properly able to test as compiling :sql as a dependency now fails intermittently with SQL.Application.start/2 is undefined in queries.ex, maybe because use SQL runs ensure_all_started(:sql) at compile time and the compiler enters a race condition?

Yeah, thats my bad. I fixed that on main.

Also, I think it would be better to move this code into SQL.Pool, since it would be run for each connection in the pool instead of once for the whole pool.