Add Postgres and database tests to CI

[franciscodiazydiaz]

📝 Summary

Update GitHub Action workflow Checks to fix the issue #168

⛱ Motivation and Context

Due to the Postgres dependency, the tests for the database code were skipped. This PR increments testing coverage by enabling the database tests (RUN_DB_TESTS=1).
The docker-compose definition is used to spin up the Postgres service while keeping non-required services down.

CI Before

ok  	github.com/flashbots/mev-boost-relay/database	0.050s	coverage: 0.0% of statements

CI After

ok  	github.com/flashbots/mev-boost-relay/database	0.143s	coverage: 10.1% of statements

---

✅ I have run these commands

• make lint
• make test-race
• go mod tidy
• I have seen and agree to CONTRIBUTING.md

[codecov-commenter]

Codecov Report

Merging #199 (dee9356) into main (0ea94e6) will increase coverage by 1.48%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #199      +/-   ##
==========================================
+ Coverage   20.68%   22.17%   +1.48%     
==========================================
  Files          19       19              
  Lines        2349     2349              
==========================================
+ Hits          486      521      +35     
+ Misses       1795     1757      -38     
- Partials       68       71       +3     

Flag	Coverage Δ
unittests	22.17% <ø> (+1.48%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
database/database.go	10.17% <0.00%> (+10.17%)	⬆️

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[metachris]

Thanks for the contribution!

Looks like it's working, and perhaps it's just fine like this. I wonder if https://docs.github.com/en/actions/using-containerized-services/creating-postgresql-service-containers isn't how it's supposed to be done 🤔 But perhaps the current way is just fine

[franciscodiazydiaz]

Hey @metachris, thanks for the feedback. If you are still interested, I can give it a try at your recommendation.

[metachris]

No strong opionions on this :)

Really happy we have db tests enabled now, thanks!

If you're curious, feel free to play with it, open to further suggestions. Btw, see also #200 for minor additional cleanup