Merge pull request dart-league#102 from zarisi/fix_dart2js

fix const providers

Author: luisvt

lib/components/datepicker/month_picker.dart

@@ -5,7 +5,7 @@ part of bs_date_picker;
 @Component (selector: "bs-month-picker",
     templateUrl: 'month_picker.html',
     directives: const [coreDirectives],
-    providers: [BsDatePickerComponent])
+    providers: const [BsDatePickerComponent])
 class BsMonthPickerComponent {
   /// parent [BsDatePickerInnerComponent]
   BsDatePickerComponent datePicker;

lib/components/datepicker/year_picker.dart

@@ -5,7 +5,7 @@ part of bs_date_picker;
 @Component (selector: "bs-year-picker",
     templateUrl: 'year_picker.html',
     directives: const [coreDirectives],
-    providers: [BsDatePickerComponent])
+    providers: const [BsDatePickerComponent])
 class BsYearPickerComponent {
   /// container of the date-picker
   BsDatePickerComponent datePicker;