[ci] Fix sonar configuration

For now, we need to use java10 with sonar, until sonarjava 5.8.0
is released, which adds support for java11.
Apparantly sonar also loads the classfiles and can't yet load
java11 classes, leading to many errors
"Unsupported class file major version 55" while analyzing
the project.

Also update SONAR_TOKEN

See https://jira.sonarsource.com/browse/SONARJAVA-2877

.travis/build-sonar.sh

@@ -12,17 +12,15 @@ if ! travis_isPush; then
     exit 0
 fi
 
-#
-# for java9: enable all modules.
-# sonar plugin seems to need java.xml.bind module
-echo "MAVEN_OPTS='-Xms1g -Xmx1g --add-modules java.se'" > ${HOME}/.mavenrc
+# for sonar, we need to use java10, until sonarjava 5.8.0 is released (Sept. 2018)
+source ./install-jdk.sh -F 10 -L GPL -W $HOME/jdk
 
 (
     # disable fast fail, exit immediately, in this subshell
     set +e
 
     # Run the build
-    ./mvnw clean org.jacoco:jacoco-maven-plugin:prepare-agent package sonar:sonar -Dsonar.host.url=https://sonarcloud.io -Dsonar.login=${SONAR_TOKEN} -B -V
+    ./mvnw clean package sonar:sonar -Dsonar.login=${SONAR_TOKEN} -Psonar -B -V
 
     if [ $? -ne 0 ]; then
         log_error "Error updating sonar..."