diff --git a/Gemfile b/Gemfile
index 68547b6..60aaf99 100644
--- a/Gemfile
+++ b/Gemfile
@@ -118,7 +118,7 @@ gem 'rouge',         '~> 2.0'
 
 # See https://groups.google.com/forum/#!topic/ruby-security-ann/aSbgDiwb24s
 # and https://groups.google.com/forum/#!topic/ruby-security-ann/Dy7YiKb_pMM
-gem 'nokogiri', '~> 1.6.7', '>= 1.6.7.2'
+gem 'nokogiri', '~> 1.6.7', '>= 1.6.7.2', '< 1.6.8'
 
 # Diffs
 gem 'diffy', '~> 3.0.3'
@@ -351,3 +351,5 @@ gem 'health_check', '~> 2.1.0'
 # System information
 gem 'vmstat', '~> 2.1.1'
 gem 'sys-filesystem', '~> 1.1.6'
+
+gem "activerecord-nulldb-adapter"
diff --git a/Gemfile.lock b/Gemfile.lock
index 5511d71..38d357e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -32,6 +32,8 @@ GEM
       activemodel (= 4.2.7.1)
       activesupport (= 4.2.7.1)
       arel (~> 6.0)
+    activerecord-nulldb-adapter (0.3.3)
+      activerecord (>= 2.0.0)
     activerecord_sane_schema_dumper (0.2)
       rails (>= 4, < 5)
     activesupport (4.2.7.1)
@@ -396,7 +398,7 @@ GEM
     method_source (0.8.2)
     mime-types (2.99.2)
     mimemagic (0.3.0)
-    mini_portile2 (2.1.0)
+    mini_portile2 (2.0.0)
     minitest (5.7.0)
     mousetrap-rails (1.4.6)
     multi_json (1.12.1)
@@ -407,8 +409,8 @@ GEM
     net-ldap (0.12.1)
     net-ssh (3.0.1)
     newrelic_rpm (3.16.0.318)
-    nokogiri (1.6.8)
-      mini_portile2 (~> 2.1.0)
+    nokogiri (1.6.7.2)
+      mini_portile2 (~> 2.0.0.rc2)
       pkg-config (~> 1.1.7)
     numerizer (0.1.1)
     oauth (0.4.7)
@@ -800,6 +802,7 @@ PLATFORMS
 DEPENDENCIES
   RedCloth (~> 4.3.2)
   ace-rails-ap (~> 4.1.0)
+  activerecord-nulldb-adapter
   activerecord_sane_schema_dumper (= 0.2)
   acts-as-taggable-on (~> 4.0)
   addressable (~> 2.3.8)