Initial set-up commit
Let Strictures identify valid & invalid data
Let Strictures describe how the data was invalid
Let it check data is in a list of items
Let it check multiple conditions.

(This already worked, just adding specs.)
Remove some over-zealous specs to lighten things up.
Extract Rules module, and start a spec file for it.
Add a few more TODOs to the README
Merge github's defaults into master