Tested validation for at least one criteria present.
At least one criteria is required to create a filter.
Tests added for FilterCriteria controller.
Filled in data for the Fabricator of FilterCriteria.
Use a build of a empty FilterCriteria for model spec.
Renamed FilterCriteria to Filter.
Changed Fabricator from FilterCriteria to Filter.
Changed spec from FilterCriteriumController to FilterController.
Change FilterCriteria spec to new naming.
FiltersController added.
Resource route for Filter.
Views for FiltersController spec.
Added filters to navigation bar in header.
Added some translations regarding filters.