simplify travis docker config
simplify travis docker config

Looks like travis has updated docker version. From travis log on pre-installed docker versions:

travis_time:end:318b89e4:start=1498081607904872594,finish=1498081607908418412,duration=3545818
[0Ktravis_fold:end:before_install.2
[0Ktravis_fold:start:before_install.3
[0Ktravis_time:start:08220747
[0K$ docker -v

Docker version 17.03.1-ce, build c6d412e

travis_time:end:08220747:start=1498081607913248361,finish=1498081608086118584,duration=172870223
[0Ktravis_fold:end:before_install.3
[0Ktravis_fold:start:before_install.4
[0Ktravis_time:start:0fc1b210
[0K$ docker-compose -v

docker-compose version 1.13.0, build 1719ceb

jfroom/poc-react-invoice,jfroom/poc-react-invoice,jfroom/poc-react-invoice