add net_income_known to bulk upload

app/services/bulk_upload/lettings/row_parser.rb

@@ -287,6 +287,8 @@ private
       cap: %i[field_77],
 
       referral: %i[field_78],
+
+      net_income_known: %i[field_51],
     }
   end
 
@@ -417,6 +419,8 @@ private
 
     attributes["referral"] = field_78
 
+    attributes["net_income_known"] = field_51
+
     attributes
   end
 

spec/services/bulk_upload/lettings/row_parser_spec.rb

@@ -116,6 +116,8 @@ RSpec.describe BulkUpload::Lettings::RowParser do
             field_77: "2",
 
             field_78: "2",
+
+            field_51: "1",
           }
         end