Merge branch 'fix-repo-search-500' into 'master'

Fix 500 errors when opening the repo search API endpoint with a browser

See merge request !225

arkindex/dataimport/serializers.py

@@ -222,11 +222,16 @@ class RepositorySerializer(serializers.ModelSerializer):
         }
 
 
-class ExternalRepositorySerializer(serializers.BaseSerializer):
+class ExternalRepositorySerializer(serializers.Serializer):
     """
     Serialize a Git repository from an external API
     """
 
+    # Useless fields, added to prevent 500 errors when opening
+    # an API endpoint in the browser
+    id = serializers.IntegerField(min_value=0)
+    corpus = serializers.UUIDField()
+
     def to_representation(self, obj):
         if isinstance(obj, gitlab.v4.objects.Project):
             return {