Update rails-html-sanitizer to 1.0.4 for security warning (#1462)

Release Notes
TECH TASK: Update gem for security warning, advisory CVE-2018-3741
https://groups.google.com/d/msg/rubyonrails-security/tP7W3kLc5u4/uDy2Br7xBgAJ

Author: rdunlop

Gemfile.lock

@@ -354,7 +354,7 @@ GEM
       railties (>= 4)
       request_store (~> 1.0)
     logstash-event (1.2.02)
-    loofah (2.2.1)
+    loofah (2.2.2)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     lumberjack (1.0.11)
@@ -450,8 +450,8 @@ GEM
       activesupport (>= 3.2)
       choice (~> 0.2.0)
       ruby-graphviz (~> 1.2)
-    rails-html-sanitizer (1.0.3)
-      loofah (~> 2.0)
+    rails-html-sanitizer (1.0.4)
+      loofah (~> 2.2, >= 2.2.2)
     rails-observers (0.1.5)
       activemodel (>= 4.0)
     railties (4.2.10)