To fix multi-tenants dashboard, this change:
* Makes ZuulService a single-service
* Loads api/info endpoint onInit and use the returned value in getsourceUrl
* Adapts all component to wait for ZuulService and remove local tenant params
* Changes navigation component to not display navigations bar in tenants list
* Changes navigation to disable dashboard link in white-label setup
* Adds an index.html file
Change-Id: I7406935c236d61b1ac884f1e69666d488e36844c