Merge remote-tracking branch 'origin/bump-requirements' into 334-update-automatic-visit-subject-importer

Resolve "privacy notice and usage terms"

Closes #329

See merge request NCER-PD/scheduling-system!276

added middleware to redirect the user to a confirmation page whenever a study has a privacy_notice assigned, this is enforced and the user haven't accepted yet. superusers excluded

Resolve "possibility to remove subject"

Closes #354

See merge request NCER-PD/scheduling-system!277

add setting and middleware to enforce 2fa #358

Closes #358

See merge request NCER-PD/scheduling-system!278

fixed issue with view logout

WIP: After the update, is failing to validate forms with boolean fields.
If the boolean fields are not present, like postponed field on the test test_validation of web.tests.forms.test_StudySubjectEditForm.StudySubjectEditFormTests.

not sure how to proceed with the changes, apparently this should have raised issues before, because the docs indicate the following:
https://docs.djangoproject.com/en/2.1/ref/forms/fields/#booleanfield

test_validation (web.tests.forms.test_StudySubjectEditForm.StudySubjectEditFormTests) ... <ul class="errorlist"><li>postponed<ul class="errorlist"><li>This field is required.</li></ul></li></ul>

text-unidecode is used by faker, now they have introduced the artistic license as well as GPL, we need to check

Merge branch '329-privacy-notice' of ssh://git-r3lab-server.uni.lu:8022/NCER-PD/scheduling-system into 329-privacy-notice