This directory contains sql code for test backends for the swh.core.db
lifecycyle handling tools.

The default backend name being 'postgresql', the directory previously named as
'cli' is now 'postgresql'.

The usage of these test backends depends on the 2 mockup functions for
import_swhmodule and get_swh_backend_module defined in conftest.py

The package name must be 'test', then the 'cls' is used to select the directory
in which the sql/ subdirectory will be used to initialize/upgrade the test
database.

The idea is a configuration like:

test:
  cls: pipeline
  steps:
    - cls: postgres
      db: <dbcnx1>
    - cls: cli2
      db: <dbcnx2>

will define 2 'swh.core.db' powered backends initialized from (resp.)
'./postgresql/sql' and './cli2/sql'.
