t/01-check.t was failing due to the response from eNom:

t/01-check.t ..........
1..3
not ok 1 - Domain check returned sensible response.

ok 2 - Domain check with missing parameter threw one error
ok 3 - Domain check with missing parameter returned an error response.
Dubious, test returned 1 (wstat 256, 0x100)
Failed 1/3 subtests

The issue is that eNom now also returns the .us TLD, so in this case
the test needed to be updated.

Added enom.us to the list of expected results and the test now passes:

t/01-check.t ..
1..3
ok 1 - Domain check returned sensible response.
ok 2 - Domain check with missing parameter threw one error
ok 3 - Domain check with missing parameter returned an error response.
ok
All tests successful.