Add Gemfile with RVM config, and Gemfile.lock

This will ensure a consistent environment for anybody who needs to get
started with the website generation.
diff --git a/Gemfile b/Gemfile
new file mode 100644
index 0000000..bc46bf5
--- /dev/null
+++ b/Gemfile
@@ -0,0 +1,8 @@
+#ruby=ruby-2.1.2
+#ruby-gemset=incubator-brooklyn-site
+
+source 'https://rubygems.org'
+
+gem 'jekyll'
+gem 'therubyracer'
+gem 'link-checker'
diff --git a/Gemfile.lock b/Gemfile.lock
new file mode 100644
index 0000000..cf69053
--- /dev/null
+++ b/Gemfile.lock
@@ -0,0 +1,87 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    anemone (0.7.2)
+      nokogiri (>= 1.3.0)
+      robotex (>= 1.0.0)
+    blankslate (2.1.2.4)
+    celluloid (0.15.2)
+      timers (~> 1.1.0)
+    classifier (1.3.4)
+      fast-stemmer (>= 1.0.0)
+    coffee-script (2.2.0)
+      coffee-script-source
+      execjs
+    coffee-script-source (1.7.0)
+    colorator (0.1)
+    colorize (0.5.8)
+    execjs (2.2.1)
+    fast-stemmer (1.0.2)
+    ffi (1.9.3)
+    jekyll (2.1.0)
+      classifier (~> 1.3)
+      colorator (~> 0.1)
+      jekyll-coffeescript (~> 1.0)
+      jekyll-gist (~> 1.0)
+      jekyll-paginate (~> 1.0)
+      jekyll-sass-converter (~> 1.0)
+      jekyll-watch (~> 1.0)
+      kramdown (~> 1.3)
+      liquid (~> 2.6.1)
+      mercenary (~> 0.3.3)
+      pygments.rb (~> 0.6.0)
+      redcarpet (~> 3.1)
+      safe_yaml (~> 1.0)
+      toml (~> 0.1.0)
+    jekyll-coffeescript (1.0.0)
+      coffee-script (~> 2.2)
+    jekyll-gist (1.1.0)
+    jekyll-paginate (1.0.0)
+    jekyll-sass-converter (1.0.0)
+      sass (~> 3.2)
+    jekyll-watch (1.0.0)
+      listen (~> 2.7)
+    kramdown (1.4.0)
+    libv8 (3.16.14.3)
+    link-checker (0.7.2)
+      anemone (~> 0.7.2)
+      colorize (~> 0.5.8)
+      nokogiri (~> 1.5.5)
+      trollop (~> 2.0)
+    liquid (2.6.1)
+    listen (2.7.9)
+      celluloid (>= 0.15.2)
+      rb-fsevent (>= 0.9.3)
+      rb-inotify (>= 0.9)
+    mercenary (0.3.3)
+    nokogiri (1.5.11)
+    parslet (1.5.0)
+      blankslate (~> 2.0)
+    posix-spawn (0.3.8)
+    pygments.rb (0.6.0)
+      posix-spawn (~> 0.3.6)
+      yajl-ruby (~> 1.1.0)
+    rb-fsevent (0.9.4)
+    rb-inotify (0.9.5)
+      ffi (>= 0.5.0)
+    redcarpet (3.1.2)
+    ref (1.0.5)
+    robotex (1.0.0)
+    safe_yaml (1.0.3)
+    sass (3.3.9)
+    therubyracer (0.12.1)
+      libv8 (~> 3.16.14.0)
+      ref
+    timers (1.1.0)
+    toml (0.1.1)
+      parslet (~> 1.5.0)
+    trollop (2.0)
+    yajl-ruby (1.1.0)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  jekyll
+  link-checker
+  therubyracer
diff --git a/_config.yml b/_config.yml
index ce7524b..eb92c57 100644
--- a/_config.yml
+++ b/_config.yml
@@ -1,2 +1,2 @@
-exclude: ['LICENSE.md', 'README.md']
+exclude: ['LICENSE.md', 'README.md', 'Gemfile', 'Gemfile.lock' ]
 url: https://brooklyn.incubator.apache.org/