t: Either skip a test or run, not both

When $host was down the test crashed, because match method would be
called on an undefined value.

Also as per S24 "The C<skip()> function is called I<instead> of the some
tests (usually because they would die), and emits C<$count> SKIP markers
in the TAP output".
Merge pull request #38 from mvuets/fix-tests

t: Either skip a test or run, not both