Transfer Request - refactoring and new test cases

1) Refactoring:
   - Replace Python underscore variable with indexing.
   - Remove the "message" assertion
2)"test_create_transfer_request_404"
   - Try to create a transfer request with random id
3)"test_zone_transfer"
   - Validation that transfer_accept deleted
     after the transfer_request delete

Change-Id: If7aa1033d52b71a6e01559b6cd468d2f5e6ddf9c
2 files changed