Add (optional) Country field to Buying.Supplier DocType (fixes #5223)

Most companies have a headquarter country;

erpnext/buying/doctype/supplier/supplier.json

@@ -89,6 +89,32 @@
    "set_only_once": 0, 
    "unique": 0
   }, 
+  {
+   "allow_on_submit": 0, 
+   "bold": 0, 
+   "collapsible": 0, 
+   "fieldname": "country", 
+   "fieldtype": "Link", 
+   "hidden": 0, 
+   "ignore_user_permissions": 0, 
+   "ignore_xss_filter": 0, 
+   "in_filter": 0, 
+   "in_list_view": 0, 
+   "label": "Country", 
+   "length": 0, 
+   "no_copy": 0, 
+   "options": "Country", 
+   "permlevel": 0, 
+   "precision": "", 
+   "print_hide": 0, 
+   "print_hide_if_no_value": 0, 
+   "read_only": 0, 
+   "report_hide": 0, 
+   "reqd": 0, 
+   "search_index": 0, 
+   "set_only_once": 0, 
+   "unique": 0
+  }, 
   {
    "allow_on_submit": 0, 
    "bold": 0, 
@@ -685,7 +711,7 @@
  "issingle": 0, 
  "istable": 0, 
  "max_attachments": 0, 
- "modified": "2016-04-13 05:47:43.797061", 
+ "modified": "2016-04-28 17:36:44.742525", 
  "modified_by": "Administrator", 
  "module": "Buying", 
  "name": "Supplier", 
@@ -832,6 +858,7 @@
    "write": 0
   }
  ], 
+ "quick_entry": 0, 
  "read_only": 0, 
  "read_only_onload": 0, 
  "search_fields": "supplier_name, supplier_type", 

erpnext/buying/doctype/supplier/test_records.json

@@ -1,4 +1,10 @@
 [
+ {
+  "doctype": "Supplier",
+  "supplier_name": "_Test Supplier with Country",
+  "supplier_type": "_Test Supplier Type",
+  "country": "Greece"
+ },
  {
   "doctype": "Supplier",
   "supplier_name": "_Test Supplier",

erpnext/buying/doctype/supplier/test_supplier.py

@@ -70,3 +70,18 @@ class TestSupplier(unittest.TestCase):
         frappe.db.set_value("Supplier", "_Test Supplier", "disabled", 0)
 
         po.save()
+
+
+    def test_supplier_country(self):
+        # Test that country field exists in Supplier DocType
+        supplier = frappe.get_doc('Supplier', '_Test Supplier with Country')
+        self.assertTrue('country' in supplier.as_dict())
+
+        # Test if test supplier field record is 'Greece'
+        self.assertEqual(supplier.country, "Greece")
+
+        # Test update Supplier instance country value
+        supplier = frappe.get_doc('Supplier', '_Test Supplier')
+        supplier.country = 'Greece'
+        supplier.save()
+        self.assertEqual(supplier.country, "Greece")