upgrade ecto to 3.2 + add basic many_to_many support

[mergefailure]

No description provided.

[mergefailure]

Any thoughts

[danmarcab]

Hi @mergefailure , thanks for this!

For some reason github didn't notify me about this. I will take a look and come back to you soon.

[danmarcab]

Hi again @mergefailure , I would like to keep this small library compatible with ecto 2 and 3. I am not actually using it right now but I know some places where they are using it with ecto 2.

Ideally I would like to have some way of testing this, for example having 2 example apps, one with ecto 2 and one with ecto 3. It would be awesome if we could run this tests in a CI (maybe github actions?)

Regarding the many to many associations, it a good point, and certainly we could improve a lot on that side. Again I would need some tests written to prove this works. You can see a couple of tests written for the supported associations in the test folder.

So ideally I would like to split this into 3 tasks:

• Make tests run on CI (github actions? circleci?) done in 9d88ac9
• Make sure ecto 2 and 3 are supported (with tests)
• Add basic many to many association support (with tests)

Ping me if you want to have a deeper look to any of them.