fix(alert): add alert-dismissable class

Closes #1745

Author: bekos

src/alert/test/alert.spec.js

@@ -59,11 +59,12 @@ describe('alert', function () {
     }
   });
 
-  it('should show close buttons', function () {
+  it('should show close buttons and have the dismissable class', function () {
     var alerts = createAlerts();
 
     for (var i = 0, n = alerts.length; i < n; i++) {
       expect(findCloseButton(i).css('display')).not.toBe('none');
+      expect(alerts.eq(i)).toHaveClass('alert-dismissable');
     }
   });
 
@@ -81,10 +82,11 @@ describe('alert', function () {
     expect(scope.removeAlert).toHaveBeenCalledWith(1);
   });
 
-  it('should not show close buttons if no close callback specified', function () {
+  it('should not show close button and have the dismissable class if no close callback specified', function () {
     element = $compile('<alert>No close</alert>')(scope);
     scope.$digest();
     expect(findCloseButton(0)).toBeHidden();
+    expect(element).not.toHaveClass('alert-dismissable');
   });
 
   it('should be possible to add additional classes for alert', function () {

template/alert/alert.html

@@ -1,4 +1,4 @@
-<div class='alert' ng-class='"alert-" + (type || "warning")'>
-    <button ng-show='closeable' type='button' class='close' ng-click='close()'>&times;</button>
+<div class="alert" ng-class="{'alert-{{type || 'warning'}}': true, 'alert-dismissable': closeable}">
+    <button ng-show="closeable" type="button" class="close" ng-click="close()">&times;</button>
     <div ng-transclude></div>
 </div>