Fix warnings

closes #15
diff --git a/src/main/scala/Engine.scala b/src/main/scala/Engine.scala
index ac587d7..c4a7459 100644
--- a/src/main/scala/Engine.scala
+++ b/src/main/scala/Engine.scala
@@ -1,6 +1,6 @@
 package org.example.similarproduct
 
-import org.apache.predictionio.controller.IEngineFactory
+import org.apache.predictionio.controller.EngineFactory
 import org.apache.predictionio.controller.Engine
 
 case class Query(
@@ -23,7 +23,7 @@
   score: Double
 ) extends Serializable
 
-object SimilarProductEngine extends IEngineFactory {
+object SimilarProductEngine extends EngineFactory {
   def apply() = {
     new Engine(
       classOf[DataSource],