S allius/pytest (#211)

* - fix pytest setup that can be startet from the rootdir
  - support python venv environment
  - add pytest.ini
  - move common settings from .vscode/settings.json into pytest.ini
  - add missing requirements
  - fix import paths for pytests

* - support python venv environment

* initial version

* - add missing requirements python-dotenv

* fix import paths for pytests

* fix pytest warnings

* initial version

* report 5 slowest test durations

* add more vscode settings for python

app/tests/test_modbus.py

@@ -1,8 +1,8 @@
 # test_with_pytest.py
 import pytest
 import asyncio
-from app.src.modbus import Modbus
-from app.src.infos import Infos, Register
+from modbus import Modbus
+from infos import Infos, Register
 
 pytest_plugins = ('pytest_asyncio',)