Code review comment for ~tcuthbert/charm-grafana:master

Known issue is causing test failure:

2020-07-28 17:42:36 [INFO] ======================================================================
2020-07-28 17:42:36 [INFO] FAIL: test_11_dashboard_upgrade (tests.test_grafana.CharmOperationTest)
2020-07-28 17:42:36 [INFO] Test upgraded dashboards are imported.
2020-07-28 17:42:36 [INFO] ----------------------------------------------------------------------
2020-07-28 17:42:36 [INFO] Traceback (most recent call last):
2020-07-28 17:42:36 [INFO] File "./tests/test_grafana.py", line 156, in test_11_dashboard_upgrade
2020-07-28 17:42:36 [INFO] self.assertTrue(chk(dashes))
2020-07-28 17:42:36 [INFO] AssertionError: False is not true
2020-07-28 17:42:36 [INFO] ----------------------------------------------------------------------

This issue is unrelated to this change, mentioning here just for completeness.

LGTM, +1