Bump org.sonarqube from 6.2.0.5505 to 6.3.1.5724

Bumps org.sonarqube from 6.2.0.5505 to 6.3.1.5724.

---
updated-dependencies:
- dependency-name: org.sonarqube
  dependency-version: 6.3.1.5724
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

gradle/libs.versions.toml

@@ -49,4 +49,4 @@ mockk = "io.mockk:mockk:1.14.5"
 nexus = { id = "io.github.gradle-nexus.publish-plugin", version = "2.0.0" }
 checker = { id = "org.checkerframework", version.ref = "checkerp" }
 jacoco = { id = "org.barfuin.gradle.jacocolog", version = "3.1.0" }
-sonar = { id = "org.sonarqube", version =  "6.2.0.5505" }
+sonar = { id = "org.sonarqube", version =  "6.3.1.5724" }