[LTP] [PATCH v2] travis: Use centos:7 instead of centos:6

[Cyril Hrubis]

Hi!
> Does have anything block this patch? Or, we should listen some advise 
> from Jan and Cyril?

I would be for dropping centos 6 (if nobody objects) after next release,
which will happen in a couple of weeks anyways.

So for now on I would be for adding centos 7, so that the next release
compiles cleanly both on centos 6 and 7.

Then we can work on our minimal requirements and drop obsolete code.

-- 
Cyril Hrubis
chrubis@suse.cz