Update to elasticsearch 1.4.0

Related to #14.

(cherry picked from commit 964de0d)

Author: dadoonet

src/main/java/org/elasticsearch/script/python/PythonScriptEngineService.java

@@ -182,11 +182,6 @@ public void setNextSource(Map<String, Object> source) {
             lookup.source().setNextSource(source);
         }
 
-        @Override
-        public void setNextScore(float score) {
-            pyVars.__setitem__("_score", Py.java2py(score));
-        }
-
         @Override
         public void setNextVar(String name, Object value) {
             pyVars.__setitem__(name, Py.java2py(value));