128 fix speakers list (#137)
128 fix speakers list (#137)

* Remove null=True from TextFields and CharFields.

* Remove null=True from URLField.

* merge conflict fix.

* merge fix

* Fix #128 List only approved speakers.

* Replace constant with variable

pyconsk/django-konfera,Matusf/django-konfera,kapucko/django-konfera,Matusf/django-konfera,pyconsk/django-konfera,kapucko/django-konfera