v0.4.0

- kubectx A=B now renames the context instead of
  aliasing.

v0.3.1

- Fix readlink bug on macOS

v0.3.0

- Add kubens tool
- Add --with-short-names installation option
- Fix variables leaking to zsh session in completion

Add zsh completion script (finally)

Signed-off-by: Ahmet Alp Balkan <ahmetb@google.com>

Update README.md