Bump loofah from 2.2.3 to 2.4.0 (#315)

Bumps [loofah](https://github.com/flavorjones/loofah) from 2.2.3 to 2.4.0.
- [Release notes](https://github.com/flavorjones/loofah/releases)
- [Changelog](https://github.com/flavorjones/loofah/blob/master/CHANGELOG.md)
- [Commits](flavorjones/loofah@v2.2.3...v2.4.0)

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

Author: dependabot[bot]

Gemfile.lock

@@ -100,7 +100,7 @@ GEM
     concurrent-ruby (1.1.3)
     crack (0.4.3)
       safe_yaml (~> 1.0.0)
-    crass (1.0.4)
+    crass (1.0.6)
     database_cleaner (1.6.2)
     datetime_picker_rails (0.0.7)
       momentjs-rails (>= 2.8.1)
@@ -206,7 +206,7 @@ GEM
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
       ruby_dep (~> 1.2)
-    loofah (2.2.3)
+    loofah (2.4.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     lumberjack (1.0.12)
@@ -230,7 +230,7 @@ GEM
     nenv (0.3.0)
     netrc (0.11.0)
     nio4r (2.2.0)
-    nokogiri (1.10.8)
+    nokogiri (1.10.9)
       mini_portile2 (~> 2.4.0)
     notiffany (0.1.1)
       nenv (~> 0.1)