Update charted to 0.4.8 and roll

packages/unittest/CHANGELOG.md

+##0.11.7
+
+* Add separate methods for `expectAysnc` based on number of callback arguments 
+  `expectAsync0`, `expectAsync1`, ... `expectAsync6`.
+* Fix all strong mode warnings.
+
+##0.11.6+4
+
+* Fix some strong mode warnings we missed in the `vm_config.dart` and
+  `html_config.dart` libraries.
+
+##0.11.6+3
+
+* Fix a bug introduced in 0.11.6+2 in which operator matchers broke when taking
+  lists of matchers.
+
+##0.11.6+2
+
+* Fix all strong mode warnings.
+
 ##0.11.6+1
 
 * Give tests more time to start running.
 
 ##0.11.6
 
 * Merge in the last `0.11.x` release of `matcher` to allow projects to use both
   `test` and `unittest` without conflicts.
 
 * Fix running individual tests with `HtmlIndividualConfiguration` when the test
@@ skipping 116 matching lines @@
 * **NEW!** `expectAsyncUntil` replaces the now deprecated `expectAsyncUntil0`,
     `expectAsyncUntil1` and `expectAsyncUntil2`
 * `TestCase`:
     * Removed properties: `setUp`, `tearDown`, `testFunction`
     * `enabled` is now get-only
     * Removed methods: `pass`, `fail`, `error`
 * `interactive_html_config.dart` has been removed.
 * `runTests`, `tearDown`, `setUp`, `test`, `group`, `solo_test`, and
   `solo_group` now throw a `StateError` if called while tests are running.
 * `rerunTests` has been removed.