Composer Dev(deps-dev): Bump wp-phpunit/wp-phpunit from 6.6.2 to 6.7.0

Bumps [wp-phpunit/wp-phpunit](https://github.com/wp-phpunit/wp-phpunit) from 6.6.2 to 6.7.0.
- [Commits](wp-phpunit/wp-phpunit@6.6.2...6.7.0)

---
updated-dependencies:
- dependency-name: wp-phpunit/wp-phpunit
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

composer.json

@@ -97,6 +97,6 @@
         "newfold-labs/wp-php-standards": "^1.2.4",
         "roave/security-advisories": "dev-latest",
         "wp-cli/i18n-command": "^2.6.3",
-        "wp-phpunit/wp-phpunit": "^6.6.2"
+        "wp-phpunit/wp-phpunit": "^6.7.0"
     }
 }