Add ArgoCD cli step templates

[harrisonmeister]

This PR introduces 5 new step templates:

1. Argo - argocd app get
2. Argo - argocd app set
3. Argo - argocd app set (with package)
4. Argo - argocd app sync
5. Argo - argocd app wait

Pre-requisites

• Id should be a GUID that is not 00000000-0000-0000-0000-000000000000
  • NOTE If you are modifying an existing step template, please make sure that you do not modify the Id property (updating the Id will break the Library sync functionality in Octopus).
• Version should be incremented, otherwise the integration with Octopus won't update the step template correctly
• Parameter names should not start with $
• Step template parameter names (the ones declared in the JSON, not the script body) should be prefixed with a namespace so that they are less likely to clash with other user-defined variables in Octopus (see this issue). For example, use an abbreviated name of the step template or the category of the step template).
• LastModifiedBy field must be present, and (optionally) updated with the correct author
• The best practices documented here have been applied
• If a new Category has been created:
  • An image with the name {categoryname}.png must be present under the step-templates/logos folder
  • The switch in the humanize function in gulpfile.babel.js must have a case statement corresponding to it

[adamoctoclose]

Tested importing into my instance and all look good to me.