Remove singleton expected query object.

test/unit/query/search.js
	-Rather than maintaining a "singleton" expected query object,
	which poses problems for tests that want to slightly modify it
	(for instance, by conditionally adding a constraint to
	`filter.bool.must`), make a function that returns it on demand,
	thereby creating a new one each time.

test/unit/query/search.js

@@ -71,7 +71,8 @@ var sort = [
   }
 ];
 
-var expected = {
+function createExpectedQuery(){
+  return {
     'query': {
       'filtered': {
         'query': {
@@ -108,7 +109,7 @@ var expected = {
     'size': 10,
     'track_scores': true
   };
-
+}
 module.exports.tests.query = function(test, common) {
   test('valid query', function(t) {
     var query = generate({
@@ -123,7 +124,7 @@ module.exports.tests.query = function(test, common) {
       layers: ['test']
     });
 
-    t.deepEqual(query, expected, 'valid search query');
+    t.deepEqual(query, createExpectedQuery(), 'valid search query');
     t.end();
   });
 
@@ -139,7 +140,7 @@ module.exports.tests.query = function(test, common) {
       layers: ['test']
     });
     
-    t.deepEqual(query, expected, 'valid search query');
+    t.deepEqual(query, createExpectedQuery(), 'valid search query');
     t.end();
   });