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

Resolve "configurable study fields"

Closes #339

See merge request NCER-PD/scheduling-system!265

Resolve "clean configuration"

Closes #343

See merge request NCER-PD/scheduling-system!271

Resolve "fix datetime without TZ warnings"

Closes #360

See merge request NCER-PD/scheduling-system!272

Resolve "branding"

Closes #357

See merge request NCER-PD/scheduling-system!273

Resolve "should we remove __unicode__ method?"

Closes #356

See merge request NCER-PD/scheduling-system!274