remove parsettl.dart

Author: zheyxu

lib/rdflib.dart

@@ -4,7 +4,6 @@ export 'src/term.dart';
 export 'src/namespace.dart';
 export 'src/triple.dart';
 export 'src/graph.dart';
-export 'src/turtle/parsettl.dart';
 
 export 'parser/naive_parser.dart';
 export 'parser/grammar_parser.dart';