Run in background

Signed-off-by: Michal Čihař <michal@cihar.com>

.travis.yml

@@ -21,6 +21,5 @@ script:
   - docker ps -a
   - curl http://127.0.0.1:8090/ | grep -q input_password
   - curl --cookie-jar /tmp/cj --location -d pma_username=root -d pma_password=my-secret-pw -d server=1 http://127.0.0.1:8090/ | grep -r 'db via TCP'
-  - docker-compose build
-  - docker-compose up
+  - docker-compose up -d
   - curl http://127.0.0.1:8080/ | grep -q input_password