Use latest/ directory for docs instead of stable/ (#3766)
Use latest/ directory for docs instead of stable/ (#3766)

See also
https://github.com/GoogleCloudPlatform/google-cloud-python/pull/3763

$ sed -i '' 's/googlecloudplatform.github.io\/google-cloud-python\/stable\//googlecloudplatform.github.io\/google-cloud-python\/latest\//g' **/*.rst
googleapis/python-cloud-core,googleapis/python-cloud-core