Update charted to 0.4.8 and roll

packages/which/test/candidate_paths_test.dart

-
-library which.test.candidate_paths;
-
-import 'package:unittest/unittest.dart';
-
-import 'util.dart';
-
-main() {
-  group('getCandidatePaths', () {
-    test('posix', () {
-      var candidatePaths = getPosixCandidatePaths('z', '/x/y:/a/b/c', '/foo/bar');
-      expect(candidatePaths, ['/x/y/z', '/a/b/c/z']);
-    });
-
-    test('windows', () {
-      var candidatePaths = getWindowsCandidatePaths('z', r'C:\x\y;C:\a\b\c', '.EXE;.BAT', r'C:\foo\bar');
-      expect(candidatePaths, [
-        r'C:\foo\bar\z.EXE',
-        r'C:\foo\bar\z.BAT',
-        r'C:\x\y\z.EXE',
-        r'C:\x\y\z.BAT',
-        r'C:\a\b\c\z.EXE',
-        r'C:\a\b\c\z.BAT']);
-    });
-  });
-}