Better extension for documentation
Ignore buildout artifacts
Move README to the root for better GitHub visibility
Add a missing test dependency
Ignore some test output variations:

    ...
    Not found: /tmp/tmp...buildouttests/zc.buildout/
    Not found: /tmp/tmp...buildouttests/zc.buildout/
    Not found: /tmp/tmp...buildouttests/setuptools/
    Not found: /tmp/tmp...buildouttests/setuptools/
    ...
Fail if the script generated from ``cmds`` returns with a non-zero exit/status code.