Add travis tests for hhvm + php 5.6

[ihor-sviziev]

I think we should test Magento with latest PHP version 5.6(for now it R2, but thavis allow use it for tests) and HHVM

[verklov]

@igor-svizev, as you know hhvm is not officially supported by Magento 2, so adding such tests is out of our priorities. Also, the officially supported versions of PHP are 5.4 and 5.5. So far we are not talking about anything related to PHP 5.6. Things can change as the time goes and one day we will go for PHP 5.6 when we have such decision approved, but not yet.

As an option, I guess you may fork the official Magento 2 repository and apply the pull request there. Anyway, thank you for your contribution! If our system requirements change with the time, we may get back to this pull request. So far we are closing it.

[ihor-sviziev]

@verklov few days ago released php 5.6. Do you plan support it?

[verklov]

@igor-svizev, I found out that in about a month we will have internally the ability to test the developed code versus PHP 5.6. However that does not mean we will have all errors encountered under 5.6 fixed immediately or that system requirements will be modified to reflect the support of the new PHP version.

I guess we will gradually move towards officially supporting PHP 5.6. Quite possibly that in some time closer to the release we will be supporting it officially. However, at this time I will not promise this will happen for sure. Taking into account the amount of code and the amount of work we have in the backlog, we are moving towards new software versions gradually. Otherwise we would be sitting and fixing issues that arise with each new version of each component upgraded :-) instead of making code changes that our community waits for.

So be a little bit more patient. We are definitely looking at new versions, though it may seem we are a little bit slow.