Sphinxcontrib-redoc

- Add support for the following ReDoc options:

- ``lazy-rendering``
- ``suppress-warnings``
- ``hide-hostname``
- ``required-props-first``
- ``expand-responses``

[:issue:`4`, :pr:`5`]

- Do not copy assets (i.e. ``redoc.js``) to output directory if Sphinx build
was finished with errors. [:issue:`1`]

- First public release.