upgrade loofah [CVE-2018-8048]

Gemfile.lock

@@ -121,7 +121,7 @@ GEM
       activerecord
       kaminari-core (= 1.1.1)
     kaminari-core (1.1.1)
-    loofah (2.2.0)
+    loofah (2.2.1)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     mail (2.7.0)
@@ -283,4 +283,4 @@ DEPENDENCIES
   uglifier (>= 1.3.0)
 
 BUNDLED WITH
-   1.16.0
+   1.16.1