update travis

.travis.yml

@@ -1,3 +1,5 @@
+sudo: required
+
 language: python
   
 python:
@@ -9,8 +11,14 @@ env:
 services:
   - docker
 
-install:
+before_install:
+  - sudo rm /usr/local/bin/docker-compose
+  - curl -L https://github.com/docker/compose/releases/download/${DOCKER_COMPOSE_VERSION}/docker-compose-`uname -s`-`uname -m` > docker-compose
+  - chmod +x docker-compose
+  - sudo mv docker-compose /usr/local/bin
   - chmod u+x ./dbench
+
+install:
   - ./dbench --setup
   - ./dbench --init
   - pip install --upgrade virtualenv