Tidy up some things that snuck through the rebase

opentech/apply/dashboard/views.py

-from django.contrib.postgres.search import SearchVector
-from django.db.models import TextField
-from django.db.models.functions import Cast
-from django.views.generic import DetailView
-
 from django_filters.views import FilterView
 from django_tables2.views import SingleTableMixin
 
@@ -19,10 +14,6 @@ class DashboardView(SingleTableMixin, FilterView):
     filterset_class = SubmissionFilter
 
 
-class SubmissionDetailView(DetailView):
-    model = ApplicationSubmission
-
-
 class SearchView(SingleTableMixin, FilterView):
     template_name = 'dashboard/search.html'
     table_class = DashboardTable