message: start changelog for 0.38
diff: +0.38.0 / 2020-06-XX
  +===================
  + * Marked `kube::runtime` module as deprecated
  + * `Config::timeout` can now be overridden to `None` (with caveats) #280
  +
  0.37.0 / 2020-06-20
  ===================
  * Bump `k8s-openapi` to `0.9.0`
  