fix(bb): download url

lib/models/bitbucket.dart

@@ -70,6 +70,7 @@ class BbTree {
   String type;
   String path;
   int size;
+  Map<String, dynamic> links;
   BbTree();
   factory BbTree.fromJson(Map<String, dynamic> json) => _$BbTreeFromJson(json);
 }

lib/models/bitbucket.g.dart

@@ -122,11 +122,13 @@ BbTree _$BbTreeFromJson(Map<String, dynamic> json) {
   return BbTree()
     ..type = json['type'] as String
     ..path = json['path'] as String
-    ..size = json['size'] as int;
+    ..size = json['size'] as int
+    ..links = json['links'] as Map<String, dynamic>;
 }
 
 Map<String, dynamic> _$BbTreeToJson(BbTree instance) => <String, dynamic>{
       'type': instance.type,
       'path': instance.path,
       'size': instance.size,
+      'links': instance.links,
     };

lib/screens/bb_object.dart

@@ -21,10 +21,11 @@ class BbObjectScreen extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final auth = Provider.of<AuthModel>(context);
     return RefreshStatefulScaffold(
       title: AppBarTitle(path ?? 'Files'),
       fetchData: () async {
-        final res = await Provider.of<AuthModel>(context)
+        final res = await auth
             .fetchBb('/repositories/$owner/$name/src/$ref/${path ?? ''}');
         if (res.headers[HttpHeaders.contentTypeHeader] == 'text/plain') {
           return res.body;
@@ -58,7 +59,7 @@ class BbObjectScreen extends StatelessWidget {
                 size: v.type == 'commit_file' ? v.size : null,
                 url:
                     '/bitbucket/$owner/$name/src/$ref?path=${v.path.urlencode}',
-                downloadUrl: null,
+                downloadUrl: v.links['self']['href'] as String,
               ),
           ]);
         } else {