Fix travis-ci build

test/test_helper.rb

@@ -1,15 +1,16 @@
 require 'bundler'
 require 'bundler/setup'
 
+homebrew_path = Pathname(`brew --prefix`.chomp)
+homebrew_path = Pathname('/usr/local') unless homebrew_path.exist?
+
 # add cask lib to load path
-brew_cask_path = Pathname.new(File.expand_path(__FILE__+'/../../../homebrew-cask/'))
+brew_cask_path = homebrew_path.join('Library', 'Taps', 'caskroom', 'homebrew-cask')
 lib_path = brew_cask_path.join('lib')
 
 $:.push(lib_path)
 
 # add homebrew to load path
-homebrew_path = Pathname(`brew --prefix`.chomp)
-homebrew_path = Pathname('/usr/local') unless homebrew_path.exist?
 $:.push(homebrew_path.join('Library', 'Homebrew'))
 
 # require homebrew testing env