Enable CI tests per openstack release
diff --git a/.travis.yml b/.travis.yml
index 08d84af..ceebb08 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -17,8 +17,9 @@
   - bundle install
 
 env:
-  - PLATFORM=trevorj/salty-whales:trusty
-  - PLATFORM=trevorj/salty-whales:xenial
+  - PLATFORM=trevorj/salty-whales:trusty OS_VERSION=mitaka
+  - PLATFORM=trevorj/salty-whales:xenial OS_VERSION=mitaka
+  - PLATFORM=trevorj/salty-whales:xenial OS_VERSION=newton
 
 before_script:
   - set -o pipefail