diff --git a/Gemfile.lock b/Gemfile.lock
index a7c6ec9..20c3084 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -246,7 +246,8 @@ GEM
       ffi (~> 1.0)
     redcarpet (3.6.0)
     ref (2.0.0)
-    rexml (3.2.5)
+    rexml (3.3.3)
+      strscan
     rouge (3.26.0)
     ruby2_keywords (0.0.5)
     rubyzip (2.3.2)
@@ -261,6 +262,7 @@ GEM
       faraday (>= 0.17.3, < 3)
     simpleidn (0.2.1)
       unf (~> 0.1.4)
+    strscan (3.1.0)
     terminal-table (1.8.0)
       unicode-display_width (~> 1.1, >= 1.1.1)
     therubyracer (0.12.3)