Moved tests.py under tests directory
Added lots of sample files and tests

* uncovered a couple bugs with strings
* sample files may be useful to other projects
Strings must be double quoted only
Fixed string tests
flatten test data dir and add expected output into file.
nosetests generator
when `pwd` == "tests/", dirname() return blank. fixed.
i hate unnecessary imports.
no consensus on key name restrictions yet. obey letter, not spirit.
Merge branch 'tests-refactor' into dev