allows for 0 _ttl's without time signifier and enables tests
Cleaned up ghoneycutt's code a tad

Signed-off-by: Ken Barber <ken@bob.sh>
Merge branch 'ttl_checking'

* ttl_checking:
  Cleaned up ghoneycutt's code a tad
  allows for 0 _ttl's without time signifier and enables tests