Clean up temporary directory in tests

After cleaning up the other warnings and converting warnings to
errors, there was a new error raised about not properly cleaning
up a temporary directory created in tests.

primed/cdsa/tests/test_commands.py

@@ -18,6 +18,9 @@ def setUp(self):
         self.tmpdir = tempfile.TemporaryDirectory()
         self.outdir = os.path.join(self.tmpdir.name, "test_output")
 
+    def tearDown(self):
+        self.tmpdir.cleanup()
+
     def test_output(self):
         out = StringIO()
         call_command("cdsa_records", self.outdir, "--no-color", stdout=out)