Updated loofah gem (CVE-2018-16468).

Gemfile.lock

@@ -225,7 +225,7 @@ GEM
     logging (2.2.2)
       little-plugger (~> 1.1)
       multi_json (~> 1.10)
-    loofah (2.2.2)
+    loofah (2.2.3)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     lumberjack (1.0.12)