Bump org.yaml:snakeyaml from 2.6 to 2.7

Bumps org.yaml:snakeyaml from 2.6 to 2.7.

---
updated-dependencies:
- dependency-name: org.yaml:snakeyaml
  dependency-version: '2.7'
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

modello-plugins/modello-plugin-snakeyaml/pom.xml

@@ -24,7 +24,7 @@
     <dependency>
       <groupId>org.yaml</groupId>
       <artifactId>snakeyaml</artifactId>
-      <version>2.6</version>
+      <version>2.7</version>
     </dependency>
   </dependencies>