Organize exports

Author: haarts

lib/logger.dart

@@ -5,9 +5,11 @@ export 'src/ansi_color.dart';
 
 export 'src/filters/debug_filter.dart';
 export 'src/filters/production_filter.dart';
+
 export 'src/outputs/console_output.dart';
 export 'src/outputs/stream_output.dart';
 export 'src/outputs/memory_output.dart';
+
 export 'src/printers/pretty_printer.dart';
 export 'src/printers/logfmt_printer.dart';