code: function versioningPHP ( obj, dest, ns ) {
          var contents = '<?php\n';
          contents += 'return array(\n';
          contents += '    \'' + ns + '\' => array(\n';
          for ( var key in obj ) {
              if ( obj.hasOwnProperty( key ) ) {
                  contents += '        \'' + key + '\' => array(\n';
                  contents += '            \'css\' => array(\n';
                  contents += extractFiles( obj[ key ].css );
                  contents += '            ),\n';
                  contents += '            \'js\' => array(\n';
                  contents += extractFiles( obj[ key ].js );
                  contents += '            ),\n';
                  contents += '        ),\n';
              }
          }
          contents += '    )\n';
          contents += ');\n';
  
          grunt.log.subhead( 'Generating PHP config file' );
          grunt.file.write( dest + '/assets.config.php', contents );
          grunt.log.ok( 'File "' + dest + '/assets.config.php" created.' );
      }
docs: Generate a PHP config file
  
  @todo   Determine if keeping these in this file is the right approach
  
  @param  {Object} obj  Versioning object created by the task
  @param  {String} dest Location to save the generated config file
  @param  {String} ns   Namespace to wrap config content
  @return {undefined}