Downgraded some dependencies.

Gemfile

@@ -55,3 +55,6 @@ gem 'rdoc'
 gem 'bootsnap'
 gem 'prawn'
 gem 'prawn-table'
+
+gem "rails-html-sanitizer", "= 1.0.3"
+gem "loofah", "= 2.0.3"

Gemfile.lock

@@ -56,7 +56,6 @@ GEM
       execjs
     coffee-script-source (1.12.2)
     concurrent-ruby (1.1.4)
-    crass (1.0.4)
     erubi (1.8.0)
     execjs (2.7.0)
     ffi (1.10.0)
@@ -75,8 +74,7 @@ GEM
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
       ruby_dep (~> 1.2)
-    loofah (2.2.3)
-      crass (~> 1.0.2)
+    loofah (2.0.3)
       nokogiri (>= 1.5.9)
     mail (2.7.1)
       mini_mime (>= 0.1.1)
@@ -118,8 +116,8 @@ GEM
     rails-dom-testing (2.0.3)
       activesupport (>= 4.2.0)
       nokogiri (>= 1.6)
-    rails-html-sanitizer (1.0.4)
-      loofah (~> 2.2, >= 2.2.2)
+    rails-html-sanitizer (1.0.3)
+      loofah (~> 2.0)
     railties (5.2.2)
       actionpack (= 5.2.2)
       activesupport (= 5.2.2)
@@ -186,10 +184,12 @@ DEPENDENCIES
   jbuilder
   jquery-rails
   listen
+  loofah (= 2.0.3)
   prawn
   prawn-table
   puma
   rails (~> 5.2.0)
+  rails-html-sanitizer (= 1.0.3)
   rdoc
   sass-rails
   spring