Use better key for events table.
Use better key for events table.

Event is not unique by its time. It is possible to receive same
event for two tasks with the same timestamp.

iverberk/nomad-ui,jippi/hashi-ui,Wintermute1/hashi-ui,Wintermute1/hashi-ui,Wintermute1/hashi-ui,maytechnet/nomad-ui,jippi/hashi-ui,iverberk/nomad-ui,maytechnet/nomad-ui,maytechnet/nomad-ui,iverberk/nomad-ui,jippi/hashi-ui,Wintermute1/hashi-ui,maytechnet/nomad-ui