Document missing task resources handling

CHANGELOG.md

@@ -40,6 +40,7 @@ BUG FIXES:
     the client [GH-1641]
   * discovery/jobspec: Validate service name after interpolation [GH-1852]
   * driver/docker: Fix `local/` directory mount into container [GH-1830]
+  * jobspec: Tasks without a resource block no longer fail to validate [GH-1864]
 
 ## 0.4.1 (August 18, 2016)
 

nomad/structs/structs.go

@@ -2103,6 +2103,7 @@ func (t *Task) Canonicalize(job *Job, tg *TaskGroup) {
 		service.Canonicalize(job.Name, tg.Name, t.Name)
 	}
 
+	// If Resources are nil initialize them to defaults, otherwise canonicalize
 	if t.Resources == nil {
 		t.Resources = DefaultResources()
 	} else {