EAGLESIX-2651: make create method in Push Accumulator static

lib/pipeline/accumulators/PushAccumulator.js

@@ -36,7 +36,7 @@ proto.reset = function reset() {
 	this.values = [];
 };
 
-proto.create = function create() {
+klass.create = function create() {
 	return new PushAccumulator();
 };