Uses new containerized Travis build system

[migmruiz]

https://docs.travis-ci.com/user/migrating-from-legacy/

[rorygraves]

Based on the fact travis actually passes with this I'm going to merge.

[gslowikowski]

+sudo: false can be removed. False is default value.

This file is very similar to the one in my Java/Scala/Maven test projects. I have no sudo setting.

From Travis docs (above link):

If you see This job is running on container-based infrastructure in your build log it means you are already running builds on our new container-based infrastructure.

If you don’t, to use the new infrastructure add the following line to your .travis.yml:

sudo: false

Check Travis logs. There is This job is running on container-based infrastructure line. This one one is from latest build.

[rorygraves]

Whoops - looks like I was a bit hasty on that merge.

[gslowikowski]

No, it's OK, removing sudo option is just small improvement you can commit separately.

[rorygraves]

Yeah I'll drop that in today