tests: end-2-end tests first draft: - e2e tests are launched inside the new docker e2e test environment - `run_e2e.py` launch the docker container, mount the current code base in it, launch the e2e tests and print report in real time - `conftest.py` are pytest fixtures managing many things such as account creation, fake files management, JSON or Domish.Element parsing, fake editor, etc. - `test_jp.py` are end-to-end test done with `jp`. `sh` library is used to make tests writting as user-friendly as possible. The `SAT_TEST_ENV_E2E` environment variable is checked, and tests will be skipped if it's not set.