Trial updated travis config from bundle

[redthor]

I'm bringing over the .travis.yml from https://github.com/doesntmattr/mongodb-migrations-bundle

[redthor]

For some reason I get PHPUnit 1.2.1-16-g26f34f8 instead of PHPUnit 5.0.0. That's why two builds are failing.

I've raised a ticket with travis: travis-ci/travis-ci#9400

[redthor]

@caciobanu this build passes now.

We could merge this and then create a 1.2.2 release entitled php 5.6 release. Then we can start work on our 2.0.0 updates. If we need to support php5.6 we can go from 1.2.2 knowing the build should be all good.

Let me know what you think. Thanks.

[caciobanu]

We should support PHP 7.1+ for 2.0.