Merge pull request #101 from huikang/fix-docker-version-ci

Fix gate docker version

Author: mestery

.travis.yml

@@ -4,7 +4,7 @@ dist: trusty
 
 env:
   - global:
-    - DOCKER_VERSION=1.11.2-0~trusty
+    - DOCKER_VERSION=1.12.0-0~trusty
 
 before_install:
     # list docker-engine versions