Add missing test logs on CI failure

Author: buchdag

.travis.yml

@@ -45,8 +45,10 @@ script:
 after_failure:
   - docker logs $NGINX_CONTAINER_NAME
   - docker logs docker_api
+  - docker logs default_cert
   - docker logs certs_single
   - docker logs certs_san
+  - docker logs force_renew
   - docker logs symlinks
   - docker logs boulder
   - if [[ $SETUP = "3containers" ]]; then docker logs $DOCKER_GEN_CONTAINER_NAME; fi