fixed failing tests

spec/helpers/tree_helper_spec.rb

@@ -9,6 +9,7 @@ describe TreeHelper do
     before do
       @id = sha
       @project = project
+      @lfs_blobs = []
     end
 
     it 'displays all entries without a warning' do

spec/views/projects/tree/show.html.haml_spec.rb

@@ -9,6 +9,7 @@ describe 'projects/tree/show' do
   before do
     assign(:project, project)
     assign(:repository, repository)
+    assign(:lfs_blobs, [])
 
     allow(view).to receive(:can?).and_return(true)
     allow(view).to receive(:can_collaborate_with_project?).and_return(true)