TST: Reorganize only the test_environment.py tests into Integration/Unit Tests

[lucasfourier]

Pull request type

• [ ] Code changes (bugfix, features)
• [X] Code maintenance (refactoring, formatting, tests)
• [ ] ReadMe, Docs and GitHub updates
• [ ] Other (please describe):

Checklist

• [ ] Tests for the changes have been added (if needed)
• [ ] Docs have been reviewed and added / updated
• [X] Lint (black rocketpy/ tests/) has passed locally
• [X] All tests (pytest tests -m slow --runslow) have passed locally
• [ ] CHANGELOG.md has been updated (if relevant)

Current behavior

Currently, the folder tests/integration is empty.

New behavior

Integration tests folder is no longer empty and contains integration tests. They are not new, they were simply moved to the right place.

Breaking change

• [ ] Yes
• [X] No

Additional information

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 71.92%. Comparing base (5f57e5f) to head (622ae81). Report is 1 commits behind head on develop.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #577 +/- ## =========================================== - Coverage 73.73% 71.92% -1.81% =========================================== Files 70 70 Lines 10334 10334 =========================================== - Hits 7620 7433 -187 - Misses 2714 2901 +187 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[Gui-FernandesBR]

@lucasfourier , why moving just some of the tests of the tests from tests/test_environment.py instead of all of them? What does set these tests apart?

[lucasfourier]

Because the tests that have been moved can be defined as integration tests as opposed to the remaining ones. The fundamental trait is the communication with external dependencies.

[Gui-FernandesBR]

@lucasfourier Can you please re-work on this branch to move all the integration tests at once instead of just some of the tests?

[Gui-FernandesBR]

@lucasfourier what is the reason for these methods be considered integration and not unit tests? They were moved from unit tests to the integration tests.

1. test_environment_export_environment_exports_valid_environment_json
2. test_date_aware_set_date_saves_custom_timezone
3. test_date_naive_set_date_saves_utc_timezone_by_default

The definition of unit and integration are not clear enough. I think it is important that you write down these definition before proceeding with any changes in this PR. This should take a few minutes, but save you from questions like the 3 above.

[lucasfourier]

@Gui-FernandesBR You are 100% right. For some reason i thought pytz made some http request at some point, but it does not. Every test there is an unit test, thank you.

[lucasfourier]

Tests with connection to API'S/interfaces were moved into the integration folder and therefore are only run with --runslow flag, just for the record.