Consider moving test dependecies changes (fixing #617) to 1.1.0

[philwebb]

Fix #617 could cause existing applications to break on upgrade since previous test dependencies will no longer be present. We should consider if this kind of change might be better for 1.1 where we can also document it in an upgrade guide.

[dsyer]

The app won't break, only the build (and only then if not using spring-boot-starter-test), so I'd be OK with it. Up to you.

[philwebb]

I'm thinking it would be better in 1.1, esp as we want people to jump to 1.0.1 quickly. I'd like 1.0.1 to be a low risk upgrade.