Merge branch 'hotfix/9'

Close #9
Added PHP 5.6 and HHVM to travis.yml
Allow failures for hhvm
Merge pull request #10 from Nyholm/patch-1

Added PHP 5.6 and HHVM to travis.yml
[#10] Allow newer versions of php-cs-fixer
Merge branch 'hotfix/10' into develop

Forward port #10