[LTP] [PATCH] travis: Add centos7 build

[Petr Vorel]

Hi Xu,

> I have this idea when I meet ALG_SET_AEAD_ASSOCLEN undefined error on centos7.
> Add centos7 travis target, it is more friendly for centos7 user and it is more
> meaningful than centos6.

OK, how about replacing CentOS 6 with CentOS 7?

Kind regards,
Petr

> I have tested this patch on my ltp fork:
> https://travis-ci.org/github/xuyang0410/ltp/jobs/720541105

> Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
> ---
>  .travis.yml | 4 ++++
>  1 file changed, 4 insertions(+)

> diff --git a/.travis.yml b/.travis.yml
> index e8e3189af..281ec9e96 100644
> --- a/.travis.yml
> +++ b/.travis.yml
> @@ -47,6 +47,10 @@ matrix:
>            env: DISTRO=centos:6 TREE=out
>            compiler: gcc

> +        - os: linux
> +          env: DISTRO=centos:7 TREE=out
> +          compiler: gcc
> +
>          - os: linux
>            env: DISTRO=debian:testing
>            compiler: gcc