add PHP 5.6 to .travis.yml
Merge pull request #51 from sasezaki/patch-1

add PHP 5.6 to .travis.yml
Added PHP 5.6

PHP 5.6 is now available: https://launchpad.net/~ondrej/+archive/ubuntu/php5-5.6

Added this as the standard option of PHP version, so we push people forward.
Merge pull request #52 from rdohms/patch-2

Added PHP 5.6 as the default version
small correction for php5-6
Added htop and iotop to system packages
Merge pull request #53 from Pegasuz/master

Added htop and iotop to system packages