"test" and "ci" should have their own environment

[ddahan]

• Currently we're using env overriding when running pytest (in pyproject.toml). Here are the potential issues:
  • Env overriding is not very clean as "test" and "ci" don't have their own environment.
  • It's very confusing to set up and could lead to unexpected errors.
  • CI overriding makes no sense as there should be only one db, not two like in local.
  • It's not 12factors compliant as config is in code
  • We could technically erase prod database in some circumstances