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

@@ -96,7 +96,7 @@ GEM
       execjs
     coffee-script-source (1.12.2)
     concurrent-ruby (1.1.5)
-    crass (1.0.4)
+    crass (1.0.5)
     devise (4.7.1)
       bcrypt (~> 3.0)
       orm_adapter (~> 0.1)
@@ -149,7 +149,7 @@ GEM
       mongoid
     launchy (2.4.3)
       addressable (~> 2.3)
-    loofah (2.2.3)
+    loofah (2.3.1)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     mail (2.7.1)
@@ -167,7 +167,7 @@ GEM
       activemodel (>= 5.1, < 6.0.0)
       mongo (>= 2.5.1, < 3.0.0)
     nio4r (2.3.1)
-    nokogiri (1.10.4)
+    nokogiri (1.10.5)
       mini_portile2 (~> 2.4.0)
     orm_adapter (0.5.0)
     poltergeist (1.18.1)