Test on Ruby 2.1.1

The current stable version of Ruby is 2.1.1 so gollum-lib should be tested there.
Fix tests on Ruby 2.1.1
Merge pull request #69 from bootstraponline/ruby_2.1.1_test_fix

Fix tests on Ruby 2.1.1
pygments.rb is much better at highlighting

Match bash and unknown language highlighting to GitHub
Allow static rendering of markdown

require 'rubygems'
require 'gollum-lib'

markup = Gollum::Markup.new(false)

markup.render_default '**hi**'
Add font awesome class to anchors in TOC generation

Use fa-link
Fix anchors for identical content

 #Summary
 #2-Summary
Make pygments.rb optional

Default to pygments when installed

Fix warning about test_path