* add trailing commas on list/map/parameters

* add trailing commas on Invocation with nb of arg>1

* add commas for widget containing widgets

* add trailing commas if instantiation contains trailing comma

* revert bad change

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests

* Upgrade everything except matcher.
* Roll matcher (and test)
* Adjust tests that depend on flutter:test directly to depend on a shim
* Require use of package:test shim and remove other references to package:test

It was causing problems rolling Flutter into Fuchsia

* re-enable lint unnecessary_const

* remove trailling whitespaces

* remove unnecessary const (after merge)

This reverts commit cc1cf13e.

* Use engine-built dart sdk

* Download dart-sdk from engine

* Move up deps to fix dart sdk constraint problem

* Update update_dart_sdk.ps1 for Windows

* Fix tests so they pass analysis

* More types for tests

* Roll engine

* Update dart sdk stamp location in flutter.bat

* Add newline

This broke the coverage tool, as material/animated_icons/animated_icons.dart
was loaded twice as a part, once directly animated_icons_private_test, and one
through animated_icons_private_test->flutter_tester->...->material

The coverage package assumes a 1:1 mapping between VM scripts and URIs due to a
limitation in the underlying vm_service_client package, which currently doesn't
provide a unique identifier for VM scripts.

The underlying issue is tracked by dart-lang/coverage#194.

This started breaking the analyzer following https://github.com/flutter/flutter/pull/13889
The test version of the material_animated_icons did not include the meta
package (needed for the @required tag) and was also not including all
the generated icons files.

Ideally we should find a way to fix this without enumerating all the
icons in the test file.
But for now just adding the missing file to fix the build breakage.