Admins may want to have discussions or any other general activity
that does not have any particular speaker. Thus, speaker validation
is removed.
Closes https://github.com/openSUSE/osem/issues/2520
Also, in events#show and proposals#index
It is more relevant to check if the speakers have registered to the
conference and filled their biographies than the submitter, because,
there can be multiple speakers and the submitter isn't necessarily one
of them
And, remove admin/events/reports.html.haml, since, it isn't used anymore
Fix#1477, fix#1479
Activate versioning for tests
The tests were failing because of the lack of versioning.By default, versioning is off for tests.
As a result, here (app/views/proposal/_form.html.haml L43) commercial,versions.last returns nil as there are no versions.
