make ApplicationFee.refunds a list object instead of array

r? @jimdanz, @kyleconroy
hmm, this looks fine for me:

 32     if (json.isJsonArray()) {
 33       Type refundListType = new TypeToken<List<FeeRefund>>() {}.getType();
 34       List<FeeRefund> refunds = gson.fromJson(json, refundListType);
 35       FeeRefundCollection collection = new FeeRefundCollection();
 36       collection.setData(refunds);
 37       collection.setHasMore(false);
 38       collection.setTotalCount(refunds.size());
 39       return collection;
 40     }
 41     else {
 42       return gson.fromJson(json, typeOfT);
 43     }
 44   }
 45 }