Update README examples with new platform versions
Update README examples with new platform versions

Some of our examples require that we specify supported platform
versions. This is not a bug, simply maintenance of our documentation.

Signed-off-by: Tom Duffield <64b2b6d12bfe4baae7dad3d018f8cbf6b0e7a044@tomduffield.com>

chef/mixlib-install,chef/mixlib-install,chef/mixlib-install