SpringBoot Upgrade to Maven Resolver 1.6.3

Comment From: wilkinsona

This is more involved than I had anticipated due to the deprecation of DefaultServiceLocator. It may not be worth the effort, for now at least.

Comment From: wilkinsona

Let's repurpose this to upgrade to 1.6.3 instead. That will be a more straightforward way to pick up the fix for https://issues.apache.org/jira/browse/MRESOLVER-153.