Add ending colon to error messages

timesheet.py

@@ -17,7 +17,7 @@ class TimesheetLine:
     def __setup__(cls):
         super(TimesheetLine, cls).__setup__()
         cls._error_messages.update({
-                'delete_invoiced_line': 'You can not delete invoiced line',
+                'delete_invoiced_line': 'You can not delete invoiced line.',
                 })
 
     @classmethod

work.py

@@ -68,9 +68,9 @@ class Work:
                     },
                 })
         cls._error_messages.update({
-                'missing_product': 'There is no product on work "%s"',
-                'missing_list_price': 'There is no list price on work "%s"',
-                'missing_party': 'There is no party on work "%s"',
+                'missing_product': 'There is no product on work "%s".',
+                'missing_list_price': 'There is no list price on work "%s".',
+                'missing_party': 'There is no party on work "%s".',
                 })
 
     @staticmethod