Testing: postgres db backend (#711)

* try postgres run

* fix yaml

* test with postgres

* check with postgres

* inkey_from

* remove trio

* add coverage

* add coverage

* more python testing

* use @pytest_asyncio.fixture

* remove unused imports

* fix api_payment payment lookup

* measure durations

docs/devs/development.md

@@ -17,7 +17,7 @@ Tests
 
 This project has unit tests that help prevent regressions. Before you can run the tests, you must install a few dependencies:
 ```bash
-./venv/bin/pip install pytest pytest-asyncio requests trio mock
+./venv/bin/pip install pytest pytest-asyncio pytest-cov requests mock
 ```
 
 Then to run the tests: