gemfile bump

use wdm on Windows boxes

Gemfile

@@ -1,2 +1,3 @@
 source "https://rubygems.org"
 gem "github-pages", group: :jekyll_plugins
+gem 'wdm', '>= 0.1.0' if Gem.win_platform?

Gemfile.lock

@@ -22,7 +22,7 @@ GEM
     ffi (1.9.14-x64-mingw32)
     forwardable-extended (2.6.0)
     gemoji (2.1.0)
-    github-pages (93)
+    github-pages (94)
       activesupport (= 4.2.7)
       github-pages-health-check (= 1.2.0)
       jekyll (= 3.2.1)
@@ -30,7 +30,7 @@ GEM
       jekyll-feed (= 0.5.1)
       jekyll-gist (= 1.4.0)
       jekyll-github-metadata (= 2.0.2)
-      jekyll-mentions (= 1.1.3)
+      jekyll-mentions (= 1.2.0)
       jekyll-paginate (= 1.1.0)
       jekyll-redirect-from (= 0.11.0)
       jekyll-sass-converter (= 1.3.0)
@@ -72,7 +72,8 @@ GEM
     jekyll-github-metadata (2.0.2)
       jekyll (~> 3.1)
       octokit (~> 4.0)
-    jekyll-mentions (1.1.3)
+    jekyll-mentions (1.2.0)
+      activesupport (~> 4.0)
       html-pipeline (~> 2.3)
       jekyll (~> 3.0)
     jekyll-paginate (1.1.0)
@@ -123,12 +124,15 @@ GEM
     sawyer (0.7.0)
       addressable (>= 2.3.5, < 2.5)
       faraday (~> 0.8, < 0.10)
-    terminal-table (1.6.0)
+    terminal-table (1.7.0)
+      unicode-display_width (~> 1.1)
     thread_safe (0.3.5)
     typhoeus (0.8.0)
       ethon (>= 0.8.0)
     tzinfo (1.2.2)
       thread_safe (~> 0.1)
+    unicode-display_width (1.1.1)
+    wdm (0.1.1)
 
 PLATFORMS
   ruby
@@ -136,6 +140,7 @@ PLATFORMS
 
 DEPENDENCIES
   github-pages
+  wdm (>= 0.1.0)
 
 BUNDLED WITH
    1.12.5