Clean up flash display in views (#2336)

* Add flashes partial to DRY up admin/auth layouts

* Further consolidate flash messages

app/views/layouts/admin.html.haml

@@ -13,13 +13,7 @@
       .content
         %h2= yield :page_title
 
-        - if flash[:notice]
-          .flash-message.notice
-            %strong= flash[:notice]
-
-        - if flash[:alert]
-          .flash-message.alert
-            %strong= flash[:alert]
+        = render 'flashes'
 
         = yield
 

app/views/layouts/auth.html.haml

@@ -9,13 +9,7 @@
           = image_tag 'logo.png'
 
     .form-container
-      - if flash[:notice]
-        .flash-message.notice
-          %strong= flash[:notice]
-
-      - if flash[:alert]
-        .flash-message.alert
-          %strong= flash[:alert]
+      = render 'flashes'
 
       = yield