set posting date in salalry slip

erpnext/hr/doctype/salary_slip/test_records.json

@@ -36,6 +36,7 @@
   ], 
   "employee": "_T-Employee-0001", 
   "employee_name": "_Test Employee", 
+  "posting_date": "2013-02-01",
   "fiscal_year": "_Test Fiscal Year 2013", 
   "month": "01", 
   "payment_days": 31, 

erpnext/patches.txt

@@ -330,3 +330,5 @@ execute:frappe.db.sql("update `tabTimesheet` ts, `tabEmployee` emp set ts.employ
 erpnext.patches.v7_1.update_lead_source
 erpnext.patches.v7_1.fix_link_for_customer_from_lead
 erpnext.patches.v7_0.update_mode_of_payment_type
+execute:frappe.reload_doctype("Salary Slip")
+execute:frappe.db.sql("update `tabSalary Slip` set posting_date=creation")