Merge pull request #131 from FoamyGuy/update_secrets_use

Update secrets usage

Author: dhalbert

adafruit_pyportal/network.py

@@ -119,8 +119,8 @@ def image_converter_url(self, image_url, width, height, color_depth=16):
         with the given width and height. aio_username and aio_key must be
         set in secrets."""
         try:
-            aio_username = self._secrets["aio_username"]
-            aio_key = self._secrets["aio_key"]
+            aio_username = self._get_setting("AIO_USERNAME")
+            aio_key = self._get_setting("AIO_KEY")
         except KeyError as error:
             raise KeyError(
                 "\n\nOur image converter service require a login/password to rate-limit. Please register for a free adafruit.io account and place the user/key in your secrets file under 'aio_username' and 'aio_key'"  # pylint: disable=line-too-long