chore(cloudinit): remove superfluous check
feat(tests): add cover script
Merge pull request #104 from jonboulle/tests

feat(tests): add coverage script
Merge pull request #99 from jonboulle/simple

chore(cloudinit): remove superfluous check
refactor(*): rework cloudconfig for better extensibility and consistency

This change creates a few simple interfaces for coreos-specific
configuration options and moves things to them wherever possible; so if
an option needs to write a file, or create a unit, it is acted on
exactly the same way as every other file/unit that needs to be written
during the cloud configuration process.
refactor(*): simplify based on bcwaldon's feedback