set TEST_AUTHOR

Test::Perl::Critic states as recommended usage for CPAN distribution authors to make the execution of the tests dependent on the existence of a TEST_AUTHOR environment variable - cf https://metacpan.org/module/Test::Perl::Critic#SYNOPSIS

I think it is a good idea to set this variable during the "disttest" step, so that these tests will be executed when shipit is performing the tests.