Fetch only once even if that host exists several times in server_list.yaml
Allow same "label" in one "servers"
Merge pull request #44 from hirose31/feature/squash-dup-host

Fetch only once even if that host exists several times in server_list.yaml
Merge pull request #45 from hirose31/feature/squash-dup-label

Allow same "label" in one "servers"