diff --git a/Gemfile b/Gemfile
index 8ef4f22..0910813 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,9 +1,11 @@
 source 'https://rubygems.org'
 
 group :development do
-  gem "rake"
-  gem "yard", "~> 0.7"
-  gem "rdoc", ">= 3.2.0"
+  gem "rake", "~> 11.0"
+  gem "activesupport", "~> 4.2"
+  gem "yard", "~> 0.9"
+  gem "json", "~> 2.1.0"
+  gem "rdoc", "~> 5.0.0"
   gem "bundler", ">= 1.0.0"
   gem "shoulda", ">= 0"
   gem "mocha", ">= 0"
diff --git a/Gemfile.lock b/Gemfile.lock
index b528470..626f344 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,40 +1,45 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (4.2.5.1)
+    activesupport (4.2.10)
       i18n (~> 0.7)
-      json (~> 1.7, >= 1.7.7)
       minitest (~> 5.1)
       thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
-    i18n (0.7.0)
-    json (1.8.3)
+    concurrent-ruby (1.0.5)
+    i18n (0.9.1)
+      concurrent-ruby (~> 1.0)
+    json (2.1.0)
     metaclass (0.0.4)
-    minitest (5.8.3)
-    mocha (1.1.0)
+    minitest (5.11.1)
+    mocha (1.3.0)
       metaclass (~> 0.0.1)
-    rake (10.4.2)
-    rdoc (4.2.2)
-      json (~> 1.4)
+    rake (11.3.0)
+    rdoc (5.0.0)
     shoulda (3.5.0)
       shoulda-context (~> 1.0, >= 1.0.1)
       shoulda-matchers (>= 1.4.1, < 3.0)
-    shoulda-context (1.2.1)
+    shoulda-context (1.2.2)
     shoulda-matchers (2.8.0)
       activesupport (>= 3.0.0)
-    thread_safe (0.3.5)
-    tzinfo (1.2.2)
+    thread_safe (0.3.6)
+    tzinfo (1.2.4)
       thread_safe (~> 0.1)
-    yard (0.7.5)
+    yard (0.9.12)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
+  activesupport (~> 4.2)
   bundler (>= 1.0.0)
+  json (~> 2.1.0)
   minitest (>= 5.0.0)
   mocha
-  rake
-  rdoc (>= 3.2.0)
+  rake (~> 11.0)
+  rdoc (~> 5.0.0)
   shoulda
-  yard (~> 0.7)
+  yard (~> 0.9)
+
+BUNDLED WITH
+   1.15.1