update rails logo

Author: mkhairi

app/views/layouts/_footer.html.slim

@@ -3,7 +3,7 @@
     .col.l6.s12
       h5.white-text Footer Content
       p.grey-text.text-lighten-4 You can use rows and columns here to organize your footer content.
-      img src="/rails-logo.svg" width="112" height="60" style="fill: white !important;"
+      = inline_svg "rails-logo.svg", class: "main-logo"
     .col.l4.offset-l2.s12
       h5.white-text Links
       ul