build(deps): 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](https://github.com/flavorjones/loofah/compare/v2.2.3...v2.3.1)

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile.lock

@@ -162,7 +162,7 @@ GEM
       carrierwave (>= 0.9)
     crack (0.4.3)
       safe_yaml (~> 1.0.0)
-    crass (1.0.4)
+    crass (1.0.5)
     css_parser (1.6.0)
       addressable
     curb (0.9.10)
@@ -356,7 +356,7 @@ GEM
       railties (>= 4)
       request_store (~> 1.0)
     logstash-event (1.2.02)
-    loofah (2.2.3)
+    loofah (2.3.1)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     lumberjack (1.0.13)
@@ -385,7 +385,7 @@ GEM
     nenv (0.3.0)
     netrc (0.11.0)
     nio4r (2.3.1)
-    nokogiri (1.10.4)
+    nokogiri (1.10.5)
       mini_portile2 (~> 2.4.0)
     notiffany (0.1.1)
       nenv (~> 0.1)