Add Travis integration

.travis.yml

@@ -0,0 +1,11 @@
+language: ruby
+rvm:
+- 2.2.2
+sudo: false
+cache: bundler
+before_install:
+  - mkdir travis-phantomjs
+  - wget https://s3.amazonaws.com/travis-phantomjs/phantomjs-2.0.0-ubuntu-12.04.tar.bz2 -O $PWD/travis-phantomjs/phantomjs-2.0.0-ubuntu-12.04.tar.bz2
+  - tar -xvf $PWD/travis-phantomjs/phantomjs-2.0.0-ubuntu-12.04.tar.bz2 -C $PWD/travis-phantomjs
+  - export PATH=$PWD/travis-phantomjs:$PATH
+script: bundle exec middleman build