fix tests
fix a couple of bits to attain 100% coverage
rename *ABC to Base*
rename marshal to serialize
Added decorator validator WIP
return validator instance from validator decorator.
Added docs for validator decoratror
added validator_test
Work on mapping iteration and field validation.
Merge branch 'feature/validators' of github.com:mikeywaites/kim into feature/validators

Conflicts:
	kim/validators.py