Merge branch 'master' of https://github.com/kubernetes/kubernetes.github.io into release-1.8

* 'master' of https://github.com/kubernetes/kubernetes.github.io: (23 commits)
  concepts/configuration/manage-compute-resources-container.md: fix a conversion (#4952)
  Update authentication.md (#5281)
  Update static-pod.md for consistency
  Space needed before list in kramdown.
  Update downward-api-volume-expose-pod-information.md
  fix the command output
  fix the command output
  fix the command output
  fix the command output
  fix the command output
  Fix CRD page typo
  fix 404 page
  Update binary_release.md
  Update disruptions.md
  fix the command output
  fix typo
  fix the command output
  Fix curl does not work in zsh
  use the term 'node' for consistency
  fix typo
  ...

docs/concepts/storage/volumes.md

@@ -112,11 +112,11 @@ Some uses for an `emptyDir` are:
   container serves the data
 
 By default, `emptyDir` volumes are stored on whatever medium is backing the
-machine - that might be disk or SSD or network storage, depending on your
+node - that might be disk or SSD or network storage, depending on your
 environment.  However, you can set the `emptyDir.medium` field to `"Memory"`
 to tell Kubernetes to mount a tmpfs (RAM-backed filesystem) for you instead.
 While tmpfs is very fast, be aware that unlike disks, tmpfs is cleared on
-machine reboot and any files you write will count against your container's
+node reboot and any files you write will count against your container's
 memory limit.
 
 #### Example pod