Add create auto image-update command

This adds the create subcommand, without attempting any refactoring.

NB the TODO: the image/v1alpha1 API does not yet export a const for
the name of the kind. The field `RunInterval` will likely be changed
to `Interval` (with a value field), at some point, too.

Signed-off-by: Michael Bridgen <michael@weave.works>

docs/cmd/flux_create_auto.md

@@ -32,4 +32,5 @@ being available.
 * [flux create](flux_create.md)	 - Create or update sources and resources
 * [flux create auto image-policy](flux_create_auto_image-policy.md)	 - Create or update an ImagePolicy object
 * [flux create auto image-repository](flux_create_auto_image-repository.md)	 - Create or update an ImageRepository object
+* [flux create auto image-update](flux_create_auto_image-update.md)	 - Create or update an ImageUpdateAutomation object
 

docs/cmd/flux_create_auto_image-update.md

@@ -0,0 +1,42 @@
+## flux create auto image-update
+
+Create or update an ImageUpdateAutomation object
+
+### Synopsis
+
+The create auto image-update command generates an ImageUpdateAutomation resource.
+An ImageUpdateAutomation object specifies an automated update to images
+mentioned in YAMLs in a git repository.
+
+```
+flux create auto image-update <name> [flags]
+```
+
+### Options
+
+```
+      --author-email string      the email to use for commit author
+      --author-name string       the name to use for commit author
+      --branch string            the branch to push commits to
+      --commit-template string   a template for commit messages
+      --git-repo-ref string      the name of a GitRepository resource with details of the upstream git repository
+  -h, --help                     help for image-update
+```
+
+### Options inherited from parent commands
+
+```
+      --context string      kubernetes context to use
+      --export              export in YAML format to stdout
+      --interval duration   source sync interval (default 1m0s)
+      --kubeconfig string   path to the kubeconfig file (default "~/.kube/config")
+      --label strings       set labels on the resource (can specify multiple labels with commas: label1=value1,label2=value2)
+  -n, --namespace string    the namespace scope for this operation (default "flux-system")
+      --timeout duration    timeout for this operation (default 5m0s)
+      --verbose             print generated objects
+```
+
+### SEE ALSO
+
+* [flux create auto](flux_create_auto.md)	 - Create or update resources dealing with automation
+