Correct matrix formatting x2.

.travis.yml

@@ -21,7 +21,15 @@ env:
 
 matrix:
   allow_failures:
-    - env: distribution=centos
+    - env:
+      - distribution: centos
+        version: 6
+        init: /sbin/init
+        run_opts: ""
+      - distribution: centos
+        version: 7
+        init: /usr/lib/systemd/systemd
+        run_opts: "--privileged --volume=/sys/fs/cgroup:/sys/fs/cgroup:ro"
 
 services:
   - docker