Bump loofah from 2.2.3 to 2.3.1

Bumps [loofah](https://github.com/flavorjones/loofah) from 2.2.3 to 2.3.1. - [Release notes](https://github.com/flavorjones/loofah/releases) - [Changelog](https://github.com/flavorjones/loofah/blob/master/CHANGELOG.md) - [Commits](flavorjones/loofah@v2.2.3...v2.3.1) Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Gemfile.lock

@@ -59,7 +59,7 @@ GEM
  coffee-script-source (1.12.2)
  concurrent-ruby (1.1.5)
  connection_pool (2.2.2)
- crass (1.0.4)
+ crass (1.0.5)
  database_cleaner (1.7.0)
  diff-lcs (1.3)
  dotenv (2.5.0)
@@ -106,7 +106,7 @@ GEM
  rb-fsevent (~> 0.9, >= 0.9.4)
  rb-inotify (~> 0.9, >= 0.9.7)
  ruby_dep (~> 1.2)
- loofah (2.2.3)
+ loofah (2.3.1)
  crass (~> 1.0.2)
  nokogiri (>= 1.5.9)
  mail (2.7.1)
@@ -120,7 +120,7 @@ GEM
  minitest (5.11.3)
  msgpack (1.3.0)
  nio4r (2.3.1)
- nokogiri (1.10.4)
+ nokogiri (1.10.5)
  mini_portile2 (~> 2.4.0)
  pastel (0.7.3)
  equatable (~> 0.6)