[FIX] New res_partner in orderpoint_calendar.yml instead of res_patner_2

The res_partner squash has added several information to the res_partner_2
Now the is a purchase order for which he's the supplier. In that case, the
planned date on the purchase order line is influenced by the planned date
of the other purchase orders where this partner is the supplier.

Here we create a new res_partner for this test who has no purchase orders related
In that case, the planned date will always the date planned in the calendar at the
basis, which is 3.

addons/stock_calendar/test/orderpoint_calendar.yml

+-
+  Create a partner
+-
+  !record {model: res.partner, id: res_partner_cal}:
+    name: Supplier
+    supplier: 1
 - 
   Create a calendar
 - 
@@ -14,7 +20,7 @@
   !record {model: product.product, id: product_calendar}:
     name: Calendar Product
     seller_ids:
-      - name: base.res_partner_2
+      - name: res_partner_cal
         delay: 1
     orderpoint_ids:
       - name: Product A Truck
@@ -27,7 +33,7 @@
 - 
   !record {model: stock.picking, id: pick_out_calendar}:
     name: Delivery order for procurement
-    partner_id: base.res_partner_2
+    partner_id: res_partner_cal
     picking_type_id: stock.picking_type_out
     move_lines:
         - product_id: product_calendar
@@ -40,7 +46,7 @@
 - 
   !record {model: stock.picking, id: pick_out_calendar2}:
     name: Delivery order for procurement
-    partner_id: base.res_partner_2
+    partner_id: res_partner_cal
     picking_type_id: stock.picking_type_out
     move_lines:
         - product_id: product_calendar
@@ -53,7 +59,7 @@
 - 
   !record {model: stock.picking, id: pick_out_calendar3}:
     name: Delivery order for procurement
-    partner_id: base.res_partner_2
+    partner_id: res_partner_cal
     picking_type_id: stock.picking_type_out
     move_lines:
         - product_id: product_calendar
@@ -88,5 +94,6 @@
     procurement = proc_obj.browse(cr, uid, proc_ids[0])
     assert procurement.product_qty == 17, 'It should have taken the two first pickings into account for the virtual stock for the orderpoint, not the third'
     assert datetime.datetime.strptime(procurement.next_delivery_date, DEFAULT_SERVER_DATETIME_FORMAT).weekday() == 3, 'The next delivery date should be on a Thursday'
-    assert datetime.datetime.strptime(procurement.purchase_line_id.date_planned, DEFAULT_SERVER_DATETIME_FORMAT).weekday() == 4, 'Check it has been put on the purchase line also'
+    purchase_line_id_date_planned = datetime.datetime.strptime(procurement.purchase_line_id.date_planned, DEFAULT_SERVER_DATETIME_FORMAT).weekday()
+    assert purchase_line_id_date_planned == 3, 'Check it has been put on the purchase line also, got %d' %purchase_line_id_date_planned