Add light border to rounded avatars
Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/20128
To make it clear that avatar is cropped by border radius
cc @hazelyang
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/20128
To make it clear that avatar is cropped by border radius
cc @hazelyang