have the test skip with the msg "TODO" if defined with no block

Before this would just skip with no message.  The thought is that
if a test is defined but no block is given, it is a TODO and should
skip as such.
some cleanups to the `test` and `should` method tests

Just cleaning things up a bit and removing some duplication.
Merge pull request #130 from redding/kr-skiptodo

have the test skip with the msg "TODO" if defined with no block