Fix test_env.py

This works around an issue where the temp directory can not be added to
Docker. In this case, the directory is immediately deleted, and does not
occupy significant disk space. There should be no impact to the move.

tests/unit/test_env.py

@@ -13,7 +13,11 @@ def test_env():
     Validate that you can define environment variables
     """
     ts = str(time.time())
-    with tempfile.TemporaryDirectory() as tmpdir:
+    # There appear to be some odd combinations of default dir that do
+    # not work on macOS Catalina with Docker CE 2.2.0.5, so use
+    # the current dir -- it'll be deleted immediately
+
+    with tempfile.TemporaryDirectory(dir=os.path.abspath(os.curdir)) as tmpdir:
         username = getuser()
         subprocess.check_call(
             [