Vulnerable Gem updates

* Update Loofah to mitigate CVE-2018-16468 (See flavorjones/loofah#154 for details)

* Update rake to mitigate CVE-2018-16471

* Update locked gems

Gemfile

@@ -42,7 +42,6 @@ gem 'paranoia', '< 2.1.2' # uses 2.0 for testing (no explicit requirement, yet)
 gem 'prawn', '< 2.0' # 2.0 requires ruby 2.0
 gem 'prawn-table'
 gem 'protective'
-gem 'rack'
 gem 'rails-i18n'
 gem 'rails_autolink'
 gem 'rubyzip', '~> 1.2.2'
@@ -76,9 +75,12 @@ gem 'therubyracer', platforms: :ruby
 gem 'turbolinks'
 gem 'uglifier'
 
-# security updates, can be deleted if they get in the way of updates or so
+# security updates, can be deleted or changed if they get in the way of updates or so
+gem 'loofah', '~> 2.2.3'
+gem 'rack', '~> 1.6.11'
 gem 'sprockets', '~> 3.7.2'
 
+
 group :development, :test do
   gem 'binding_of_caller'
   gem 'codez-tarantula', require: 'tarantula-rails3'