MNT Travis shared config

[emteknetnz]

Mergeup to 3 AND 4

Behat failure is an issue with chrome that we've investigated and we'll let browser auto updates deal with silverstripe/silverstripe-asset-admin#1163

Behat screenshot:
https://s3.amazonaws.com/silverstripe-travis-artifacts/silverstripe/silverstripe-graphql/208443105/459249264/screenshots/insert-an-image.feature_46.png

[Cheddam]

I'm not convinced that the Behat failure relates to the styling issue presented in that screenshot - it looks like the test is trying to find a button in the DOM and failing:

And I press the "Details" button                                # SilverStripe\BehatExtension\Context\BasicContext::stepIPressTheButton()

      Details button not found

      Failed asserting that null is not null.

I'll spend a bit of time trying to reproduce locally, would prefer not to merge red if possible.

[emteknetnz]

@Cheddam the issue is actually on asset-admin as graphql runs behat tests from different modules.

I've written an explanation on the asset-admin PR of why I think this should be merged as is