add footer to Youtube prompt

app/assets/stylesheets/main/landing.scss

@@ -114,3 +114,9 @@
 .tooltip-wrapper {
   display: inline-block;
 }
+
+ #youtube-footer{
+   font-size: 10px;
+   text-align: center;
+   margin-top: 10px; 
+ }

app/controllers/sessions_controller.rb

@@ -43,7 +43,7 @@ class SessionsController < ApplicationController
 
   def auth_failure
     if params[:message] == 'invalid_credentials'
-      redirect_to '/', flash: {danger: 'Invalid login credentials.' }
+      redirect_to '/', flash: {danger: t('invalid_login') }
     else
       redirect_to '/'
     end

app/views/landing/rooms.html.erb

@@ -76,6 +76,7 @@
             <%= t('upload') %>
           </button>
         </div>
+        <p id = 'youtube-footer'><%= t('youtube_footer') %></p>
     </form>
   </div>
   <div class='mail_youtube_popover'>