[MINOR] Addressed Docs dependency security vulnerability followup

Followup to 26428c56f20ba5ea608038ed8c2e11d8f04665d4

Author: Alex Bozarth <ajbozart@us.ibm.com>

Closes #82 from ajbozarth/gem.

(cherry picked from commit 6d2ffdd54273e7d4a75bde38527f75acc14d6ef3)
Signed-off-by: Alex Bozarth <ajbozart@us.ibm.com>
diff --git a/docs/Gemfile.lock b/docs/Gemfile.lock
index f9b0ed8..4223f8a 100644
--- a/docs/Gemfile.lock
+++ b/docs/Gemfile.lock
@@ -161,14 +161,14 @@
       rb-fsevent (>= 0.9.3)
       rb-inotify (>= 0.9.7)
     mercenary (0.3.6)
-    mini_portile2 (2.2.0)
+    mini_portile2 (2.3.0)
     minima (2.1.1)
       jekyll (~> 3.3)
     minitest (5.10.2)
     multipart-post (2.0.0)
     net-dns (0.8.0)
-    nokogiri (1.8.0)
-      mini_portile2 (~> 2.2.0)
+    nokogiri (1.8.2)
+      mini_portile2 (~> 2.3.0)
     octokit (4.7.0)
       sawyer (~> 0.8.0, >= 0.5.3)
     pathutil (0.14.0)