Replace some fmt calls with log

Signed-off-by: Izuru Yakumo <yakumo.izuru@chaotic.ninja>

cmd/aya/main.go

@@ -402,19 +402,19 @@ func main() {
 			buildAll(false)
 		} else if len(args) == 1 {
 			if err := build(args[0], os.Stdout, globals()); err != nil {
-				fmt.Println("ERROR: " + err.Error())
+				log.Fatal("ERROR: " + err.Error())
 			}
 		} else {
-			fmt.Println("ERROR: too many arguments")
+			log.Fatal("ERROR: too many arguments")
 		}
 	case "clean":
-		fmt.Println("Removing generated site directory")
+		log.Println("Removing generated site directory")
 		os.RemoveAll(PUBDIR)
 	case "serve":
 		servePubDir()
 	case "var":
 		if len(args) == 0 {
-			fmt.Println("var: filename expected")
+			log.Fatal("var: filename expected")
 		} else {
 			s := ""
 			if vars, _, err := getVars(args[0], Vars{}); err != nil {
@@ -439,9 +439,9 @@ func main() {
 		buildAll(true)
 	default:
 		if s, err := run(globals(), cmd, args...); err != nil {
-			fmt.Println(err)
+			log.Println(err)
 		} else {
-			fmt.Println(s)
+			log.Println(s)
 		}
 	}
 }