Fix build when using Ruby 2.3.1. bundler fails to install deps

when using Ruby 2.3.1 because of a compatability problem with the
JSON gem ( ruby/json#229 ).

To do this I just removed the old gem lock file and generated a new
one.

Gemfile.lock

@@ -2,46 +2,56 @@ GEM
   remote: https://rubygems.org/
   specs:
     RedCloth (4.2.9)
-    activesupport (4.1.6)
-      i18n (~> 0.6, >= 0.6.9)
-      json (~> 1.7, >= 1.7.7)
+    activesupport (5.0.0.1)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (~> 0.7)
       minitest (~> 5.1)
-      thread_safe (~> 0.1)
       tzinfo (~> 1.1)
+    addressable (2.4.0)
     blankslate (2.1.2.4)
-    celluloid (0.16.0)
-      timers (~> 4.0.0)
-    classifier-reborn (2.0.1)
+    classifier-reborn (2.0.4)
       fast-stemmer (~> 1.0)
-    coffee-script (2.3.0)
+    coffee-script (2.4.1)
       coffee-script-source
       execjs
-    coffee-script-source (1.8.0)
+    coffee-script-source (1.10.0)
     colorator (0.1)
-    execjs (2.2.2)
+    concurrent-ruby (1.0.2)
+    ethon (0.9.1)
+      ffi (>= 1.3.0)
+    execjs (2.7.0)
+    faraday (0.9.2)
+      multipart-post (>= 1.2, < 3)
     fast-stemmer (1.0.2)
-    ffi (1.9.6)
+    ffi (1.9.14)
     gemoji (2.1.0)
-    github-pages (28)
+    github-pages (39)
       RedCloth (= 4.2.9)
+      github-pages-health-check (~> 0.2)
       jekyll (= 2.4.0)
-      jekyll-coffeescript (= 1.0.0)
-      jekyll-mentions (= 0.1.3)
-      jekyll-redirect-from (= 0.6.2)
-      jekyll-sass-converter (= 1.2.0)
-      jekyll-sitemap (= 0.6.0)
-      jemoji (= 0.3.0)
-      kramdown (= 1.3.1)
-      liquid (= 2.6.1)
+      jekyll-coffeescript (= 1.0.1)
+      jekyll-feed (= 0.3.1)
+      jekyll-mentions (= 0.2.1)
+      jekyll-redirect-from (= 0.8.0)
+      jekyll-sass-converter (= 1.3.0)
+      jekyll-sitemap (= 0.8.1)
+      jemoji (= 0.5.0)
+      kramdown (= 1.5.0)
+      liquid (= 2.6.2)
       maruku (= 0.7.0)
-      pygments.rb (= 0.6.0)
+      mercenary (~> 0.3)
+      pygments.rb (= 0.6.3)
       rdiscount (= 2.1.7)
-      redcarpet (= 3.1.2)
-    hitimes (1.2.2)
+      redcarpet (= 3.3.2)
+      terminal-table (~> 1.4)
+    github-pages-health-check (0.3.2)
+      net-dns (~> 0.6)
+      public_suffix (~> 1.4)
+      typhoeus (~> 0.7)
     html-pipeline (1.9.0)
       activesupport (>= 2)
       nokogiri (~> 1.4)
-    i18n (0.6.11)
+    i18n (0.7.0)
     jekyll (2.4.0)
       classifier-reborn (~> 2.0)
       colorator (~> 0.1)
@@ -57,61 +67,75 @@ GEM
       redcarpet (~> 3.1)
       safe_yaml (~> 1.0)
       toml (~> 0.1.0)
-    jekyll-coffeescript (1.0.0)
+    jekyll-coffeescript (1.0.1)
       coffee-script (~> 2.2)
-    jekyll-gist (1.1.0)
-    jekyll-mentions (0.1.3)
+    jekyll-feed (0.3.1)
+    jekyll-gist (1.4.0)
+      octokit (~> 4.2)
+    jekyll-mentions (0.2.1)
       html-pipeline (~> 1.9.0)
       jekyll (~> 2.0)
     jekyll-paginate (1.1.0)
-    jekyll-redirect-from (0.6.2)
-      jekyll (~> 2.0)
-    jekyll-sass-converter (1.2.0)
+    jekyll-redirect-from (0.8.0)
+      jekyll (>= 2.0)
+    jekyll-sass-converter (1.3.0)
       sass (~> 3.2)
-    jekyll-sitemap (0.6.0)
-    jekyll-watch (1.1.1)
-      listen (~> 2.7)
-    jemoji (0.3.0)
+    jekyll-sitemap (0.8.1)
+    jekyll-watch (1.5.0)
+      listen (~> 3.0, < 3.1)
+    jemoji (0.5.0)
       gemoji (~> 2.0)
       html-pipeline (~> 1.9)
-      jekyll (~> 2.0)
-    json (1.8.1)
-    kramdown (1.3.1)
-    liquid (2.6.1)
-    listen (2.7.11)
-      celluloid (>= 0.15.2)
-      rb-fsevent (>= 0.9.3)
-      rb-inotify (>= 0.9)
+      jekyll (>= 2.0)
+    kramdown (1.5.0)
+    liquid (2.6.2)
+    listen (3.0.8)
+      rb-fsevent (~> 0.9, >= 0.9.4)
+      rb-inotify (~> 0.9, >= 0.9.7)
     maruku (0.7.0)
-    mercenary (0.3.4)
-    mini_portile (0.6.0)
-    minitest (5.4.2)
-    nokogiri (1.6.3.1)
-      mini_portile (= 0.6.0)
+    mercenary (0.3.6)
+    mini_portile2 (2.1.0)
+    minitest (5.9.1)
+    multipart-post (2.0.0)
+    net-dns (0.8.0)
+    nokogiri (1.6.8.1)
+      mini_portile2 (~> 2.1.0)
+    octokit (4.6.0)
+      sawyer (~> 0.8.0, >= 0.5.3)
     parslet (1.5.0)
       blankslate (~> 2.0)
-    posix-spawn (0.3.9)
-    pygments.rb (0.6.0)
+    posix-spawn (0.3.12)
+    public_suffix (1.5.3)
+    pygments.rb (0.6.3)
       posix-spawn (~> 0.3.6)
-      yajl-ruby (~> 1.1.0)
-    rb-fsevent (0.9.4)
-    rb-inotify (0.9.5)
+      yajl-ruby (~> 1.2.0)
+    rb-fsevent (0.9.8)
+    rb-inotify (0.9.7)
       ffi (>= 0.5.0)
     rdiscount (2.1.7)
-    redcarpet (3.1.2)
+    redcarpet (3.3.2)
     safe_yaml (1.0.4)
-    sass (3.4.5)
-    thread_safe (0.3.4)
-    timers (4.0.1)
-      hitimes
-    toml (0.1.1)
+    sass (3.4.22)
+    sawyer (0.8.0)
+      addressable (>= 2.3.5, < 2.6)
+      faraday (~> 0.8, < 0.10)
+    terminal-table (1.7.3)
+      unicode-display_width (~> 1.1.1)
+    thread_safe (0.3.5)
+    toml (0.1.2)
       parslet (~> 1.5.0)
+    typhoeus (0.8.0)
+      ethon (>= 0.8.0)
     tzinfo (1.2.2)
       thread_safe (~> 0.1)
-    yajl-ruby (1.1.0)
+    unicode-display_width (1.1.1)
+    yajl-ruby (1.2.1)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
   github-pages
+
+BUNDLED WITH
+   1.13.6