Bump org.gradle:gradle-core from 3.0 to 6.0 in /gradle

Bumps org.gradle:gradle-core from 3.0 to 6.0.

---
updated-dependencies:
- dependency-name: org.gradle:gradle-core
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
1 file changed