Optimize kitchen tests for Travis CI

Change-Id: I2b864114f592a4ba82e839aefe8218b85d236e3c

.kitchen.travis.yml

-suites:
-
-  - name: <%= ENV['SUITE'] %>
-    provisioner:
-      pillars-from-files:
-        mongodb.sls: tests/pillar/<%= ENV['SUITE'] %>.sls

.travis.yml

   - make test | tail
 
 script:
-  - KITCHEN_LOCAL_YAML=.kitchen.travis.yml bundle exec kitchen test -t tests/integration
+  - test ! -e .kitchen.yml || bundle exec kitchen converge ${SUITE} || true
+  - test ! -e .kitchen.yml || bundle exec kitchen verify ${SUITE} -t tests/integration
 
 notifications:
   webhooks: