Move gem dependencies into the gemspec.

Gemfile

@@ -1,14 +1,3 @@
 source "https://rubygems.org"
 
-gem 'asciidoctor'
-gem 'asciidoctor-diagram'
-gem 'git'
-gem 'guard'
-gem 'guard-shell'
-gem 'guard-livereload'
-gem 'haml'
-gem 'json'
-gem 'pandoc-ruby'
-gem 'rake'
-gem 'yajl-ruby'
-gem 'tilt'
+gemspec

doc_site_builder.gemspec

@@ -20,4 +20,17 @@ Gem::Specification.new do |spec|
 
   spec.add_development_dependency "bundler", "~> 1.7"
   spec.add_development_dependency "rake", "~> 10.0"
+
+  spec.add_dependency 'asciidoctor'
+  spec.add_dependency 'asciidoctor-diagram'
+  spec.add_dependency 'git'
+  spec.add_dependency 'guard'
+  spec.add_dependency 'guard-shell'
+  spec.add_dependency 'guard-livereload'
+  spec.add_dependency 'haml'
+  spec.add_dependency 'json'
+  spec.add_dependency 'pandoc-ruby'
+  spec.add_dependency 'rake'
+  spec.add_dependency 'yajl-ruby'
+  spec.add_dependency 'tilt'
 end