Fixed default value of notification in the verifier config file
Added instance/image id and verified_at to error messages
Added tests for verification exceptions
Merge pull request #290 from anujm/add_info_to_verification_error_messages

Added instance/image id and verified_at to error messages
Merge pull request #267 from priy1237/NOTIFICATION_DEFAULT_VALUE_FIX

Fixed default value of notification in the verifier config file