Fix README formatting
Add test for generating documentation
Add support for generating API documentation

To generate project docs using codox, run

    $ lein doc

On pushes to the github repo, travis will attempt to generate the docs
and the tests will fail if [test/tooling.sh]
(https://github.com/cddr/schema.contrib/blob/master/test/tooling.sh)
returns a non-zero exit code
Merge pull request #3 from cddr/setup-docs

Setup docs