[Feature] Volume Shortcuts

[iwilltry42]

Introducing two things:

• automatic volume creation for k3d- prefixed volumes using the --volume flag -> k3d will handle creation + deletion
• magic mount destination keywords: e.g. --volume /some/path:k3s-storage will internally be handled as /some/path:/var/lib/rancher/k3s/storage

Originally posted by @iwilltry42 in #865 (comment)

EDIT: actually, bullet point 1 is already a docker feature: if the source part of the volume mount is not a path on the local filesystem and not an existing named volume, docker will create it (k3d will still print a warning though).

[bayeslearner]

Tried latest version, still got error:

(base) ~ k3d cluster create --servers 2 -v k3d-data:k3s-storage foobar
WARN[0000] No node filter specified
FATA[0000] Failed Cluster Configuration Validation:  failed to validate volume mount 'k3d-data:k3s-storage': volume mount destination doesn't appear to be an absolute path: 'k3s-storage' in 'k3d-data:k3s-storage'
(base) ~

[iwilltry42]

@bayeslearner , damn.. didn't put the new function to use apparently 🙄
Fixed in b208c1f ... Sorry for that! (To be released with next patch/minor release)