Github CI with Postgres (#417)

* with postgres

* postgres test explicit

* make format

* start postgres only if needed

* remove if again

* print db

* db in matrix

* delete schema

* use new env var MINT_TEST_DATABASE for tests

* add db path to regtest

tests/test_mint_db.py

@@ -6,6 +6,7 @@ from cashu.mint.ledger import Ledger
 from cashu.wallet.wallet import Wallet
 from cashu.wallet.wallet import Wallet as Wallet1
 from tests.conftest import SERVER_ENDPOINT
+from tests.helpers import is_postgres
 
 
 async def assert_err(f, msg):
@@ -61,3 +62,10 @@ async def test_melt_quote(wallet1: Wallet, ledger: Ledger):
     assert quote.checking_id == invoice.payment_hash
     assert quote.paid_time is None
     assert quote.created_time
+
+
+@pytest.mark.asyncio
+@pytest.mark.skipif(not is_postgres, reason="only works with Postgres")
+async def test_postgres_working():
+    assert is_postgres
+    assert True