Feature: Introduce Super Admins (#705)

* Feature: Introduce Super Admins

- added new devise model for super user
- added administrate gem
- sample dashboards for users and accounts

Co-authored-by: Pranav Raj Sreepuram <pranavrajs@gmail.com>

spec/models/super_admin_spec.rb

@@ -0,0 +1,5 @@
+require 'rails_helper'
+
+RSpec.describe SuperAdmin, type: :model do
+  pending "add some examples to (or delete) #{__FILE__}"
+end