Renamed some tests and removed references to modeltests/regressiontests.

tests/utils_tests/os_utils.py

@@ -0,0 +1,26 @@
+import os
+
+from django.utils import unittest
+from django.utils._os import safe_join
+
+
+class SafeJoinTests(unittest.TestCase):
+    def test_base_path_ends_with_sep(self):
+        drive, path = os.path.splitdrive(safe_join("/abc/", "abc"))
+        self.assertEqual(
+            path,
+            "{0}abc{0}abc".format(os.path.sep)
+        )
+
+    def test_root_path(self):
+        drive, path = os.path.splitdrive(safe_join("/", "path"))
+        self.assertEqual(
+            path,
+            "{0}path".format(os.path.sep),
+        )
+
+        drive, path = os.path.splitdrive(safe_join("/", ""))
+        self.assertEqual(
+            path,
+            os.path.sep,
+        )