Merge pull request #81 from GetStream/fix-issue-80

Missing exports

Author: xsahil03x

packages/stream_feed/lib/src/core/models/index.dart

@@ -10,8 +10,14 @@ export 'event.dart' show Impression, Engagement, UserData, Content;
 export 'feed_id.dart';
 export 'filter.dart';
 export 'follow.dart';
+export 'follow_stats.dart';
+export 'followers.dart';
+export 'following.dart';
 export 'foreign_id_time_pair.dart';
+export 'group.dart';
 export 'open_graph_data.dart';
 export 'reaction.dart';
+export 'realtime_message.dart';
 export 'resize.dart';
+export 'thumbnail.dart';
 export 'user.dart';