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

@@ -41,7 +41,7 @@ GEM
       term-ansicolor (~> 1.3)
       thor (>= 0.19.4, < 2.0)
       tins (~> 1.6)
-    crass (1.0.4)
+    crass (1.0.5)
     descendants_tracker (0.0.4)
       thread_safe (~> 0.3, >= 0.3.1)
     diff-lcs (1.3)
@@ -74,7 +74,7 @@ GEM
       semver2
     json (2.2.0)
     jwt (2.2.1)
-    loofah (2.2.3)
+    loofah (2.3.1)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     method_source (0.9.2)
@@ -84,7 +84,7 @@ GEM
     multi_json (1.13.1)
     multi_xml (0.6.0)
     multipart-post (2.1.1)
-    nokogiri (1.10.4)
+    nokogiri (1.10.5)
       mini_portile2 (~> 2.4.0)
     oauth2 (1.4.1)
       faraday (>= 0.8, < 0.16.0)