Clean up yaml output

resource.go

@@ -32,14 +32,15 @@ func (ds ResourceStatus) String() string {
 // uniquely identified by a URL.
 type Resource struct {
 	URL         URL
-	Status      ResourceStatus
-	Pinned      bool
-	LastChecked time.Time
+	Status      ResourceStatus `yaml:"-"`
+	Pinned      bool           `yaml:"-"`
+	LastChecked time.Time      `yaml:"last_checked"`
 
 	// only set if Status == ResourceStatusError
-	ErrorString string
+	ErrorString string `yaml:"error"`
 
 	// Indicate the URLs of resources which link to/are linked from this
 	// resource.
-	IncomingLinkURLs, OutgoingLinkURLs []URL
+	IncomingLinkURLs []URL `yaml:"incoming_links"`
+	OutgoingLinkURLs []URL `yaml:"outgoing_links"`
 }