Add missing supports for kubernetes client stable and gold

according to new kubernetes client guidelines python client is beta support and has silver capabilities. We are almost there to have gold capabilities and stable support. missing parts are:

Gold:

• Support attach, port-forward calls
• Proto encoding
• Generated examples #252 #219

Stable:

• N documented users of the library
• Support level documented per-platform
• Deprecation policy (backwards compatibility guarantees documented)
• Release process well documented