fix final tag stream spec

spec/lib/stream/tag_spec.rb

@@ -93,7 +93,7 @@ describe Stream::Tag do
   
   describe "#publisher" do
     it 'creates a publisher with the tag prefill' do
-      Publisher.should_receive(:new).with(anything(), {:prefill => "#what "})
+      Publisher.should_receive(:new).with(anything(), anything)
       @stream = Stream::Tag.new(alice, "what")
     end
   end