GRN-19: Add confirmation for accepting cookies from the site (#345)

* Added a cookie warning

* Cleaned up code to better match application standard

app/assets/stylesheets/utilities/_variables.scss

@@ -0,0 +1,24 @@
+/* BigBlueButton open source conferencing system - http://www.bigbluebutton.org/.
+*
+* Copyright (c) 2018 BigBlueButton Inc. and by respective authors (see below).
+*
+* This program is free software; you can redistribute it and/or modify it under the
+* terms of the GNU Lesser General Public License as published by the Free Software
+* Foundation; either version 3.0 of the License, or (at your option) any later
+* version.
+*
+* BigBlueButton is distributed in the hope that it will be useful, but WITHOUT ANY
+* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+* PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public License along
+* with BigBlueButton; if not, see <http://www.gnu.org/licenses/>.
+*/
+// Declare all variables here.
+// They will automatically be included in application.css.
+// You can use Sass (SCSS) here: http://sass-lang.com/
+$background-color: #F5F7FB;
+$error-background-color: #EFE6E6;
+$button-color-blue: #467FCF;
+$header-height: 65px;
+$footer-height: 65px;