Update travis-ci config

[aotd1]

Added php 5.6 and hhvm builds,
Code coverage report (you can see sample here),
Automatic code style check with php_codesniffer - just run ./runTests.sh

[aotd1]

Oh, after run ./runTests.sh you can see coverage report in .reports/index.html =)

[zzantares]

Isn't scrutinizer-ci a paid service? how will this work if I'm not going to pay for this service?, I guess works ok in your fork since is linked with your github account, but in my side, if I merge your commits, that will not work in my repo, isn't it?

[aotd1]

It's free for Open-Source Repositories.
If you link your github repo it start working for you as static analysis tool. It subscribes on repository commits.

For code coverage report you need to edit build config https://scrutinizer-ci.com/g/ZzAntares/ProxmoxVE/settings/build-config

imports:
    - php
tools:
    external_code_coverage: true

Travis generate coverage report and send it to scrutinizer-ci =)

[zzantares]

Thanks Alexey, can't review this until today.