Remove unused github-linguist dependency

.travis.yml

 rvm:
   - 1.9.3
   - 2.0.0
-
-before_install:
-  - "sudo apt-get update && sudo apt-get install libicu-dev"
\ No newline at end of file

Gemfile

@@ -15,8 +15,6 @@ gem "middleman-livereload", "~> 3.1.0"
 
 gem 'redcarpet', :git => 'https://github.com/vmg/redcarpet.git'
 
-gem "github-linguist", "~> 2.9.5"
-
 # For faster file watcher updates on Windows:
 gem "wdm", "~> 0.1.0", :platforms => [:mswin, :mingw]