Add support for MySQL/MariaDB

[phihos]

This PR adds support for the Exto adapter Ecto.Adapters.MyXQL.

Closes #85.

[phihos]

I ran the tests locally and they passed. Someone needs tot trigger the CI so I can fix potential CI issues.

[crbelaus]

Thanks for this PR @phihos! It looks great, I will take a deeper look later this week. Apparently GitHub Actions doesn't like the --connect parameter and the CI is failing.

[phihos]

Hi, thanks for the feedback. I checked the health command and according to an official blogpost the command is correct. I also tried it myself and the script and its argument are accepted. I guess GH actions/docker does not like the single quotes very much. I replaced them with double quotes and added --innodb_initialized which is also recommended.

[phihos]

Fixed the formatting issue. Next run should at least go to the database tests.

[phihos]

I forgot a line in the example test config which I put in my local test config. The tables should exist now. @crbelaus Can you trigger CI again?

[phihos]

Sorry, I accidentally reverted the health-cmd fix. Should work again now.

[phihos]

I also accidentally reverted the formatter fix from yesterday 🙈
Fixed it now.

[phihos]

Finally 🥳

[crbelaus]

Honestly this is looking great. I've been playing with it and it works flawlessly. Thanks for the work @phihos

Any thoughts @odarriba ?

[odarriba]

Looks good!! Thanks for this amazing contribution ❤️

[phihos]

Thank you for merging my PR. Now I do not have to maintain a fork for my use-case. Your code was already very well structured and implementation went smoothly. Looking forward to future releases :-)

[crbelaus]

Thank you for merging my PR. Now I do not have to maintain a fork for my use-case. Your code was already very well structured and implementation went smoothly. Looking forward to future releases :-)

Thank you for contributing @phihos! BTW, we have just released v0.3.0 with MySQL/MariaDB support.