cumulus cli: Allow user delete cluster by name

[cjh1]

Currently we have to add a section to the configuration file

cumulus cluster --cluster_section=traditional delete

It would be nice to be able to do:

cumulus cluster list
Listing clusters:
Name                 Status    Cluster ID                Profile
-------------------  --------  ------------------------  ---------
home                running   58501b470640fd0a7c6ce2e2
NewtIntegrationTest  running   586e61cc0640fd2d5441901b

then

cumulus cluster home delete 

or something similar