Create "Specification Tests" to ensure compliance of language code generation or libraries

[joelgallant]

As an offshoot of #46, we should have compliance tests to ensure that a library or code generation does the right thing. This is a bit hard to do, since each environment would require different "harnesses" to check for correct behavior. A CLI test is good, but may not be deep enough to check for some behavior.

[joelgallant]

3ac506d starting point