fix fakeenv creation when used from a non-primary volume

tests/fake_env.py

@@ -92,6 +92,7 @@ class TestFakeFs(fake_filesystem_unittest.TestCase):
     def setUp(self):
         self.rootpath = os.path.abspath(os.path.dirname(__file__))
         self.setUpPyfakefs()
+        self.fs.CreateDirectory(os.path.expanduser('~'))
         self.fs.CreateDirectory(self.rootpath)
         os.chdir(self.rootpath)