travis-ci: Enable stretch (the future Debian 9), replacing unstable

My goal in building ostree for Debian unstable was that we would
have good coverage of "new code" paths. However, it was removed
for #571 as too much of a moving target. Debian testing is less of
a moving target, and in particular is always internally consistent
(packages are co-installable), which Debian unstable is not guaranteed
to be.

Debian 'stretch' is the future Debian 9, which should be released
next year.

Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Closes: #600
Approved by: cgwalters

diff --git a/.travis.yml b/.travis.yml
index bf04939cb2e209b2c02582313404392577c356fe..67bea019d0c6230a100080df2bbfbd8b0d07ddca 100644 (file)
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,7 @@ sudo: required
 env:
   - ci_distro=ubuntu ci_suite=trusty
   - ci_docker=debian:jessie-slim ci_distro=debian ci_suite=jessie
+  - ci_docker=debian:stretch-slim ci_distro=debian ci_suite=stretch
   - ci_docker=ubuntu:xenial ci_distro=ubuntu ci_suite=xenial
 
 script: