chore: removed angular2.api.ts

BREACKING CHANGE:

We export InjectMetadata instead of InjectAnnotation

modules/angular2/src/transform/common/annotation_matcher.dart

@@ -10,10 +10,6 @@ import 'logging.dart' show logger;
 /// on a class. These classes are re-exported in many places so this covers all
 /// the possible libraries which could provide them.
 const INJECTABLES = const [
-  const AnnotationDescriptor(
-      'Injectable', 'package:angular2/src/di/annotations.dart', null),
-  const AnnotationDescriptor(
-      'Injectable', 'package:angular2/src/di/annotations_impl.dart', null),
   const AnnotationDescriptor(
       'Injectable', 'package:angular2/src/di/decorators.dart', null),
   const AnnotationDescriptor('Injectable', 'package:angular2/di.dart', null),