fix filename globbing

Author: leafo

bin/moonc

@@ -178,7 +178,7 @@ function scan_directory(root, collected)
 				scan_directory(full_path, collected)
 			end
 
-			if fname:match(".moon") then
+			if fname:match("%.moon$") then
 				table.insert(collected, full_path)
 			end
 		end