More tests

[krzys-h]

In #256 I added some very basic tests to check if the views which were not covered yet, but they need to be expanded. Here is my current list of things that need to be tested more:

• article editing
• resource auth
• image uploads
• data in participant/lecturer/all people views
• data in workshop list views
• filterEmails
• dataForPlan
• header bar behaviour (who sees links to admin etc.)
• whether all of the UIs which are disabled under some conditions are properly disabled (see How did this even happen... + more tests #256...)
• other minor things which are not yet covered by tests from the coverage report (invalid parameters etc.)
• ensure that locks that trigger on a certain day trigger at midnight Europe/Warsaw time
• wwwforms: start/end date validation
• wwwforms: is_required validation
• wwwforms: submitting choice fields (select, single choice, multiple choice)