Update charted to 0.4.8 and roll

packages/which/test/util.dart

-
-library which.test.util;
-
-import 'dart:io';
-
-import 'package:mockito/mockito.dart';
-import 'package:path/path.dart' as path;
-import 'package:which/src/candidate_paths.dart';
-
-getPosixCandidatePaths(String command, String pathVar, String current) {
-  var env = {
-    'PATH': pathVar
-  };
-  var isWindows = false;
-  var context = new path.Context(style: path.Style.posix, current: current);
-
-  return getCandidatePaths(command, env, isWindows, context);
-}
-
-getWindowsCandidatePaths(String command, String pathVar, String pathExtVar, String current) {
-  var env = {
-    'PATH': pathVar,
-    'PATHEXT': pathExtVar
-  };
-  var isWindows = true;
-  var context = new path.Context(style: path.Style.windows, current: current);
-
-  return getCandidatePaths(command, env, isWindows, context);
-}
-
-class MockFileStat extends Mock implements FileStat {
-
-  MockFileStat();
-
-  noSuchMethod(i) => super.noSuchMethod(i);
-}
-
-int parseBinary(String b) => int.parse(b, radix: 2);