diff --git a/Gemfile.lock b/Gemfile.lock
index 52fceb6..364033e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -164,7 +164,8 @@ GEM
       railties (>= 3.2.16)
     json (2.1.0)
     kgio (2.11.0)
-    kramdown (1.16.2)
+    kramdown (2.3.1)
+      rexml
     launchy (2.4.3)
       addressable (~> 2.3)
     letter_opener (1.4.1)
@@ -191,7 +192,9 @@ GEM
       mimemagic (~> 0.3.2)
     memcachier (0.0.2)
     method_source (0.9.0)
-    mimemagic (0.3.2)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_magick (4.8.0)
     mini_mime (1.0.1)
     mini_portile2 (2.4.0)
@@ -266,6 +269,7 @@ GEM
     responders (2.4.0)
       actionpack (>= 4.2.0, < 5.3)
       railties (>= 4.2.0, < 5.3)
+    rexml (3.2.4)
     rolify (5.1.0)
     rspec (3.7.0)
       rspec-core (~> 3.7.0)