Bump D8 version.

[martinfrances107]

[martinfrances107]

I am just posting a comment at the moment.

Over in https://www.drupal.org/project/flag/issues/2923089

I am about to use dropwhale

I am still troubleshooting my install of dropwhale

But when I get things running I will want to test against 8.5.x which is the way testbot works.

So I suggest updating the version from

DRUPAL_BRANCH=8.3.x

to

DRUPAL_BRANCH=8.5.x

[martinfrances107]

I have create a pull request with a patch that fixes things

( see the pull request for details on how I confirmed that the change seems to work. )

From my perspective this PR is a complete solution to the issue.