add Genome::Utility::Test::Stat
give tests default names
refactor test to use Genome::Utility::Test::Stat
add test case

Setting GENOME_SYS_UMASK='0027' for 'cle' user revealed that by not
casting GENOME_SYS_UMASK as octal we were not using the expected umask.
hard-code assumption about test

Instead of depending on our current GENOME_SYS_UMASK hard-code in the
value for the test.