Add describe for deployment

[zachschuermann]

Rudimentary describe for deployments. (and also added DescItem::Valu64 in the process)

[dev] [default] [2 Deployments selected] > describe
--- alertmanager ---
Name:           alertmanager
Namespace:      default
Created at:     2016-09-24 04:23:54 UTC (2016-09-23 23:23:54 -05:00)
Generation:     47
Labels:         app=alertmanager
Desired Replicas:       1
Current Replicas:       1
Up To Date Replicas:    1
Available Replicas:     1

Containers:
  Name: prometheus-config-watcher
    Image:      registry.dev.databricks.com/universe/prometheus-config-watcher:0.6
  Name: alertmanager
    Image:      prom/alertmanager:v0.19.0

Messages:
  Message: Deployment has minimum availability.

--- metrics-search ---
Name:           metrics-search
Namespace:      default
Created at:     2018-09-14 22:07:15 UTC (2018-09-14 17:07:15 -05:00)
Generation:     4
Labels:         app=metrics-search
                project=metrics-search
Desired Replicas:       1
Current Replicas:       1
Up To Date Replicas:    1
Available Replicas:     1

Containers:
  Name: metrics-search
    Image:      registry.dev.databricks.com/universe/metrics-search:latest
  Name: auth-proxy
    Image:      registry.dev.databricks.com/oauth2_proxy:7eb7e0b95666b4c026270d4a8723c1aeb0309410-20170625-231803

Messages:
  Message: Deployment has minimum availability.

[nicklan]

Awesome! Thanks for this