Update for SonarQube 6.7

[braykov]

The LTS release is now 6.7

I get the following warnings:

• WARN: The use of the issues mode (sonar.analysis.mode=issues) is deprecated. This mode will be dropped in the future.
• WARN: Ability to set quality profile from command line using 'sonar.profile' is deprecated and will be dropped in a future SonarQube version.
• WARN: The use of "sonar.branch" is deprecated and replaced by "sonar.branch.name". See https://redirect.sonarsource.com/doc/branches.html.

The last one is most important for me as sonar.branch is now incompatible with sonar.branch.name and I cannot use the new branch feature by SonarQube.

[elboletaire]

We're still using version 6.2, so this is not a priority for us ATM.

PR are welcome btw, so feel free to make one with the required changes and we'll take care of merging it and creating a specific docker tag for it.

[elboletaire]

Done in 3.0.0.

Note that the WARN: The use of the issues mode... is still there because we're still not sure how to proceed (apparently, the sonar-gitlab-plugin creator either).