Update superset_config.py (#7)

add slack token to superset_config.py

docker/pythonpath_dev/superset_config.py

@@ -105,6 +105,7 @@ class CeleryConfig(object):
 WEBDRIVER_BASEURL = "http://superset:8088/"
 # The base URL for the email report hyperlinks.
 WEBDRIVER_BASEURL_USER_FRIENDLY = WEBDRIVER_BASEURL
+SLACK_API_TOKEN = get_env_variable("SLACK_API_TOKEN")
 
 SQLLAB_CTAS_NO_LIMIT = True