chore(security): patch rails-html-sanitizer vulnerability (#335)

Author: dependabot[bot]

Gemfile.lock

@@ -110,8 +110,8 @@ GEM
       activesupport (>= 4.2.0, < 5.0)
       nokogiri (~> 1.6)
       rails-deprecated_sanitizer (>= 1.0.1)
-    rails-html-sanitizer (1.0.3)
-      loofah (~> 2.0)
+    rails-html-sanitizer (1.3.0)
+      loofah (~> 2.3)
     railties (4.2.7.1)
       actionpack (= 4.2.7.1)
       activesupport (= 4.2.7.1)