Create 2 partials for notices and alerts:
<%= notice %>
<%= alert %>
We can also create a single partial and pass in the css_class:
<%= message %>
Logic in Application Layout:
<% if notice.present? %>
<%= render "shared/flash", message: notice, css_class: "success" %>
<% end %>
<% if alert.present? %>
<%= render "shared/flash", message: alert, css_class: "danger" %>
<% end %>
