Bump loofah from 2.2.2 to 2.3.1

Bumps [loofah](https://github.com/flavorjones/loofah) from 2.2.2 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/v2.2.2...v2.3.1)

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

Gemfile.lock

@@ -77,7 +77,7 @@ GEM
       execjs
     coffee-script-source (1.12.2)
     concurrent-ruby (1.0.5)
-    crass (1.0.4)
+    crass (1.0.5)
     css_parser (1.6.0)
       addressable
     debug_inspector (0.0.3)
@@ -150,7 +150,7 @@ GEM
     kaminari-mongoid (1.0.1)
       kaminari-core (~> 1.0)
       mongoid
-    loofah (2.2.2)
+    loofah (2.3.1)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     mail (2.7.0)
@@ -162,7 +162,7 @@ GEM
     mime-types-data (3.2016.0521)
     mimemagic (0.3.2)
     mini_mime (0.1.4)
-    mini_portile2 (2.3.0)
+    mini_portile2 (2.4.0)
     minitest (5.11.3)
     mongo (2.4.3)
       bson (>= 4.2.1, < 5.0.0)
@@ -187,8 +187,8 @@ GEM
     multi_json (1.12.2)
     multipart-post (2.0.0)
     nested_form (0.3.2)
-    nokogiri (1.8.5)
-      mini_portile2 (~> 2.3.0)
+    nokogiri (1.10.5)
+      mini_portile2 (~> 2.4.0)
     origin (2.3.1)
     orm_adapter (0.5.0)
     paperclip (5.2.0)