title: Problems with PHP YAML within Travis CI
body: <p>Edit: I believe the problem is that YAML doesn't work on 5.4/5.5.</p>
  
  <p>I have a library that is setup in Travis CI and that uses the PHP YAML PECL extension. However, I am unable to get the YAML extension to work in Travis &amp; PHP 5.4, and I'm curious if anyone else has? No amount of Googling has solved my problem.</p>
  
  <p>Here is the output of Travis:</p>
  
  <pre><code>$ git clone --depth=50 --branch="master" git://github.com/titon/IO.git titon/IO
  
  Cloning into 'titon/IO'...
  
  remote: Counting objects: 531, done.
  
  remote: Compressing objects: 100% (256/256), done.
  
  remote: Total 531 (delta 267), reused 460 (delta 196)
  
  Receiving objects: 100% (531/531), 79.41 KiB, done.
  
  Resolving deltas: 100% (267/267), done.
  
  $ cd titon/IO
  git.2
  
  $ git checkout -qf 3940a6673413da224eeaaebbc6a98167e4feda38
  
  $ phpenv global 5.4
  
  $ php --version
  
  PHP 5.4.13 (cli) (built: Mar 31 2013 06:18:12)
  
  Copyright (c) 1997-2013 The PHP Group
  
  Zend Engine v2.4.0, Copyright (c) 1998-2013 Zend Technologies
  
  with Xdebug v2.2.1, Copyright (c) 2002-2012, by Derick Rethans
  before_script.1
  
  $ sudo apt-get install libyaml-dev
  
  Reading package lists... Done
  
  Building dependency tree
  
  Reading state information... Done
  
  libyaml-dev is already the newest version.
  
  0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
  
  $ pecl install yaml
  
  downloading yaml-1.1.0.tgz ...
  
  Starting to download yaml-1.1.0.tgz (35,916 bytes)
  
  ..........done: 35,916 bytes
  
  9 source files, building
  
  WARNING: php_bin /home/travis/.phpenv/versions/5.4.13/bin/php appears to have a prefix ., but config variable php_prefix does not match
  
  WARNING: php_bin /home/travis/.phpenv/versions/5.4.13/bin/php appears to have a suffix env/versions/5.4.13/bin/php, but config variable php_suffix does not match
  
  running: phpize
  
  Configuring for:
  
  PHP Api Version: 20100412
  
  Zend Module Api No: 20100525
  
  Zend Extension Api No: 220100525
  
  Please provide the prefix of libyaml installation [autodetect] : (Waits until it times out)
  </code></pre>
  
  <p>The travis.yml in question: <a href="https://github.com/titon/IO/blob/master/.travis.yml" rel="nofollow">https://github.com/titon/IO/blob/master/.travis.yml</a></p>