Render “Staged” in task list with yellow health badge

This was the intended visual effect for the task list, but it was lost
in an earlier refactoring

* Extract the logic of a health badge into a BadgeComponent. If `type`
  is provided, the badge gets a gray badge and a health indicator.
Accept object to BadgeComponent for types

Only one “type” is assumed to be true at a time.
Merge pull request #374 from mesosphere/task-list-health-badge

Render “Staged” in task list with yellow health badge