Reorganize tests

BUG=chromium:703769
TEST=None

Change-Id: Id99f43f4aae7218d302905b53389680614ffd2ef
diff --git a/cros_venv/test_venvlib.py b/cros_venv/test_venvlib.py
index 57cd127..eb30643 100644
--- a/cros_venv/test_venvlib.py
+++ b/cros_venv/test_venvlib.py
@@ -13,54 +13,9 @@
 from cros_venv import venvlib
 
 
-class VenvTestCase(unittest.TestCase):
-
-    """TestCase for venvlib."""
-
-    def test__PACKAGE_DIR(self):
-        """Test that _PACKAGE_DIR exists."""
-        self.assertTrue(os.path.isdir(venvlib._PACKAGE_DIR))
-
-    def test__iter_equal(self):
-        """Test when _iter_equal() is True."""
-        self.assertTrue(venvlib._iter_equal(
-            iter(['foo', 'bar']),
-            iter(['foo', 'bar']),
-        ))
-
-    def test__iter_equal_wrong_length(self):
-        """Test when _iter_equal() is False due to length."""
-        self.assertFalse(venvlib._iter_equal(
-            iter(['foo', 'bar', 'baz']),
-            iter(['foo', 'bar']),
-        ))
-
-    def test__iter_equal_fill_with_None(self):
-        """Test that _iter_equal() is True due to filling with None."""
-        self.assertTrue(venvlib._iter_equal(
-            iter(['foo', 'bar', None]),
-            iter(['foo', 'bar']),
-        ))
-
-    def test__iter_equal_wrong_value(self):
-        """Test when _iter_equal() is False due to value."""
-        self.assertFalse(venvlib._iter_equal(
-            iter(['foo', 'baz']),
-            iter(['foo', 'bar']),
-        ))
-
-
 class VenvTmpDirTestCase(testcases.TmpdirTestCase):
 
-    """TestCase for venvlib that uses a temp directory."""
-
-    def test__makedirs_exist_ok(self):
-        """Test _makedirs_exist_ok() ignores existing dir."""
-        os.mkdir('foo')
-        try:
-            venvlib._makedirs_exist_ok('foo')
-        except OSError:
-            self.fail('OSError raised')
+    """TestCase for Venv that uses a temp directory."""
 
     def test__reqs_up_to_date(self):
         """Test _reqs_up_to_date()."""
@@ -99,3 +54,53 @@
         """Test _venv_initialized() with missing bin/python."""
         venv = venvlib.Venv('.', 'reqs.txt')
         self.assertFalse(venv._venv_initialized())
+
+
+class VenvlibTestCase(unittest.TestCase):
+
+    """TestCase for venvlib functions."""
+
+    def test__PACKAGE_DIR(self):
+        """Test that _PACKAGE_DIR exists."""
+        self.assertTrue(os.path.isdir(venvlib._PACKAGE_DIR))
+
+    def test__iter_equal(self):
+        """Test when _iter_equal() is True."""
+        self.assertTrue(venvlib._iter_equal(
+            iter(['foo', 'bar']),
+            iter(['foo', 'bar']),
+        ))
+
+    def test__iter_equal_wrong_length(self):
+        """Test when _iter_equal() is False due to length."""
+        self.assertFalse(venvlib._iter_equal(
+            iter(['foo', 'bar', 'baz']),
+            iter(['foo', 'bar']),
+        ))
+
+    def test__iter_equal_fill_with_None(self):
+        """Test that _iter_equal() is True due to filling with None."""
+        self.assertTrue(venvlib._iter_equal(
+            iter(['foo', 'bar', None]),
+            iter(['foo', 'bar']),
+        ))
+
+    def test__iter_equal_wrong_value(self):
+        """Test when _iter_equal() is False due to value."""
+        self.assertFalse(venvlib._iter_equal(
+            iter(['foo', 'baz']),
+            iter(['foo', 'bar']),
+        ))
+
+
+class VenvlibTmpDirTestCase(testcases.TmpdirTestCase):
+
+    """TestCase for venvlib functions that uses a temp directory."""
+
+    def test__makedirs_exist_ok(self):
+        """Test _makedirs_exist_ok() ignores existing dir."""
+        os.mkdir('foo')
+        try:
+            venvlib._makedirs_exist_ok('foo')
+        except OSError:
+            self.fail('OSError raised')