Hi Julien,
For Cobertura let say this plugin is not our priority. We are focusing on JaCoCo.
I just made a test on one of our Gradle project and using Gradle 2.13 + JaCoCo 0.7.6 + SonarQube plugin 2.0.1 works fine out of the box. Do you have any error or simply you don't see coverage in SonarQube?
Also looking at your travis.sh it seems you are mixing two features of SonarQube:
- regular/published analysis => should be executed on your master branch and will publish result on SonarQube server
- preview/pull request analysis => should be executed on pull request with parameter -Dsonar.analysis.mode=issue
In your case it seems you want to analyze your pull requests, so you need to add -Dsonar.analysis.mode=issue parameter.
++
Julien