Prepare account credit note for Tryton 8.0

tox.ini

@@ -0,0 +1,17 @@
+[tox]
+envlist = {py37,py38,py39,py310}-{sqlite,postgresql}
+
+[testenv]
+extras = test
+commands =
+    coverage run --include=./**/account_credit_note/* -m unittest discover -s tests
+    coverage report --include=./**/account_credit_note/* --omit=*/tests/*
+deps =
+    coverage
+    postgresql: psycopg2 >= 2.7.0
+setenv =
+    sqlite: TRYTOND_DATABASE_URI={env:SQLITE_URI:sqlite://}
+    postgresql: TRYTOND_DATABASE_URI={env:POSTGRESQL_URI:postgresql://}
+    sqlite: DB_NAME={env:SQLITE_NAME::memory:}
+    postgresql: DB_NAME={env:POSTGRESQL_NAME:test}
+install_command = pip install --pre --find-links https://trydevpi.tryton.org/?local_version={env:CI_JOB_ID:{env:CI_BUILD_NUMBER:}.{env:CI_JOB_NUMBER:}}&mirror=github {opts} {packages}