add message subject to the title tag

app/views/notify/pipeline_failed_email.html.haml

@@ -4,7 +4,7 @@
     %meta{:content => "text/html; charset=UTF-8", "http-equiv" => "Content-Type"}/
     %meta{:content => "width=device-width, initial-scale=1", :name => "viewport"}/
     %meta{:content => "IE=edge", "http-equiv" => "X-UA-Compatible"}/
-    %title
+    %title= message.subject
     :css
       /* CLIENT-SPECIFIC STYLES */
       body, table, td, a { -webkit-text-size-adjust: 100%; -ms-text-size-adjust: 100%; }

app/views/notify/pipeline_success_email.html.haml

@@ -4,7 +4,7 @@
     %meta{:content => "text/html; charset=UTF-8", "http-equiv" => "Content-Type"}/
     %meta{:content => "width=device-width, initial-scale=1", :name => "viewport"}/
     %meta{:content => "IE=edge", "http-equiv" => "X-UA-Compatible"}/
-    %title
+    %title= message.subject
     :css
       /* CLIENT-SPECIFIC STYLES */
       body, table, td, a { -webkit-text-size-adjust: 100%; -ms-text-size-adjust: 100%; }