Add cache control headers to the API responses to avoid IE caching th… (#1500)

Add cache control headers to the API responses to avoid IE caching the response.

api/api.go

@@ -68,6 +68,7 @@ var corsHeaders = map[string]string{
 	"Access-Control-Allow-Methods":  "GET, DELETE, OPTIONS",
 	"Access-Control-Allow-Origin":   "*",
 	"Access-Control-Expose-Headers": "Date",
+	"Cache-Control":                 "no-cache, no-store, must-revalidate",
 }
 
 // Enables cross-site script calls.