remove intermediate file used in handler

lib/image_optim.rb

@@ -75,6 +75,7 @@ def optimize_image(original)
           worker.optimize(src, dst)
         end
       end
+      handler.cleanup
       if handler.result
         ImagePath::Optimized.new(handler.result, original)
       end

lib/image_optim/handler.rb

@@ -23,5 +23,13 @@ def process
         end
       end
     end
+
+    # Remove extra temp files
+    def cleanup
+      if @dst
+        @dst.unlink
+        @dst = nil
+      end
+    end
   end
 end

spec/image_optim/handler_spec.rb

@@ -40,5 +40,9 @@
       [src, dst].should == [temp_a, temp_b]; true
     end
     handler.result.should == temp_b
+
+    temp_a.should_receive(:unlink).once
+    handler.cleanup
+    handler.cleanup
   end
 end