- Bump python version used when building documentation.
- `setuptools` is a deprecated installation method on RTD so switch to `pip`.
- Add additional dependency on devlib master branch as RTD env is not
respecting dependency_links during installation.
- Bump copyright year.
The latest sphinx and docutils versions currently used on readthedocs
are no longer compatible. Explicitly list the package versions that
should be used when building the documentation.