Bump loofah from 2.2.3 to 2.3.0 (#479)

Bumps [loofah](https://github.com/flavorjones/loofah) from 2.2.3 to 2.3.0.
- [Release notes](https://github.com/flavorjones/loofah/releases)
- [Changelog](https://github.com/flavorjones/loofah/blob/master/CHANGELOG.md)
- [Commits](https://github.com/flavorjones/loofah/commits)

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

Gemfile.lock

@@ -148,7 +148,7 @@ GEM
       railties (>= 4.2.0)
       thor (>= 0.14, < 2.0)
     json (2.2.0)
-    loofah (2.2.3)
+    loofah (2.3.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     mail (2.7.1)