discogs: add test dependencies, fix spelling

beetsplug/discogs.py

@@ -235,7 +235,7 @@ class DiscogsPlugin(BeetsPlugin):
             catalogno = None
         country = result.data.get('country')
         media = result.data['formats'][0]['name']
-        # Explicitely set the `media` for the tracks, since it is expected by
+        # Explicitly set the `media` for the tracks, since it is expected by
         # `autotag.apply_metadata`.
         for track in tracks:
             track.media = media

setup.py

@@ -106,6 +106,7 @@ setup(
         'pyxdg',
         'pathlib',
         'python-mpd2',
+        'discogs-client'
     ],
 
     # Plugin (optional) dependencies:

tox.ini

@@ -23,6 +23,7 @@ deps =
     jellyfish
     python-mpd2
     coverage
+    discogs_client
 
 [_flake8]
 deps =