fix travis failing

.travis.yml

@@ -1,4 +1,6 @@
 language: ruby
+before_install:
+  - curl -f -L "https://raw.githubusercontent.com/vim-airline/vim-airline-themes/master/autoload/airline/themes/simple.vim" -o autoload/airline/themes/simple.vim
 rvm:
   - 1.9.3
 script: rake ci

t/commands.vim

@@ -22,6 +22,8 @@ describe 'commands'
     Expect g:airline_theme == 'simple'
     execute 'AirlineTheme dark'
     Expect g:airline_theme == 'dark'
+    execute 'AirlineTheme doesnotexist'
+    Expect g:airline_theme == 'dark'
   end
 
   it 'should have a refresh command'