Add a --reporter flag and expose the expanded reporter.

CHANGELOG.md

 ### 0.12.0-beta.11
 
 * Tests, groups, and suites can now be configured on a platform-by-platform
   basis. Tests and groups are configured using the `onPlatform` named argument;
   suites are configured using the `@OnPlatform` annotation. See [the
   README][onPlatform] for more information.
 
 [onPlatform]: https://github.com/dart-lang/test/blob/master/README.md#platform-specific-configuration
 
+* Add a `--reporter` flag and an expanded reporter that prints each test on its
+  own line.
+
 * Properly ignore unrelated `link` tags in custom HTML.
 
 * Preserve the stack traces for load errors in isolates and iframes.
 
 * Stop `pub serve` from emitting a duplicate-asset error for tests with custom
   HTML files.
 
 * When running a test suite via `dart path/to/test.dart`, throw an exception if
   the suite fails so that the exit code is set properly.
 
@@ skipping 234 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.