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>

Gemfile.lock

@@ -71,7 +71,7 @@ GEM
     byebug (11.0.1)
     coderay (1.1.2)
     concurrent-ruby (1.1.5)
-    crass (1.0.4)
+    crass (1.0.5)
     declarative (0.0.10)
     declarative-option (0.1.0)
     devise (4.7.0)
@@ -137,7 +137,7 @@ GEM
     listen (3.0.8)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
-    loofah (2.2.3)
+    loofah (2.3.1)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     mail (2.7.1)
@@ -154,7 +154,7 @@ GEM
     multi_json (1.13.1)
     multipart-post (2.1.1)
     nio4r (2.5.1)
-    nokogiri (1.10.4)
+    nokogiri (1.10.5)
       mini_portile2 (~> 2.4.0)
     orm_adapter (0.5.0)
     os (1.0.1)