Revert to old method of sample data gen

bulk_create is super quick, but no autoincrement on sqlite is killer when trying to run tests.

conftest.py

@@ -29,4 +29,15 @@ def splinter_screenshot_dir():
 def vat_rate(db):
     vat_rate = VatRate.objects.create(start_at='2014-03-05', rate=0.20, comment='test1')
     yield vat_rate
-    vat_rate.delete()
+    vat_rate.delete()
+
+
+def _has_transactional_marker(item):
+    db_marker = item.get_closest_marker("django_db")
+    if db_marker and db_marker.kwargs.get("transaction"):
+        return 1
+    return 0
+
+
+def pytest_collection_modifyitems(items):
+    items.sort(key=_has_transactional_marker)