Hotfix for failing tests in master build

[SabineHaas]

Addresses #296

To test the hotfix, either #297 had to be solved first - or skip for failing tests had to be removed --> second option chosen --> todo

• add skip again before merge

Changes proposed in this pull request:

• Changed order of checks in github actions workflow - linting with black is last check now, to prevent failing due to black before pytest are run.
• Move test_examples.py to examples folder to make tests work in CI

The following steps were realized, as well (required):

• Update the CHANGELOG.md
• Check if full simulation tests pass locally (EXECUTE_TESTS_ON=master pytest)

Also the following steps were realized (if applies):

• Use in-line comments to explain your code
• Write docstrings to your code
• For new functionalities: Explain in readthedocs
• Write test(s) for your new patch of code

Please mark above checkboxes as following:

• Open
• Done

In case of an error due to linting, run black . --exclude docs/ and push your changes.
Note that in case you do not fix a whole issue you should start your PR with Address #xyz.

_{For more information on how to contribute check the CONTRIBUTING.md.}

[SabineHaas]

@MaGering @Piranias was easier than thought --> just had to move text_examples.py to the examples folder 🙈

The build passes for b3e85bb (apply black), where the tests of test_examples.py are run (skip removed).
I have now added the skip again, so that these tests are only run on master branch.

Unfortunately, I did a mistake: hotfixes are supposed to be merged into master branch, I selected dev and have already merged dev into the hotfix branch. So, as an exception we merge the hotfix to dev and it will find its way to master branch via the release branch.