[ci] Specify sonar.projectKey

Author: harawata

travis/after_success.sh

@@ -42,7 +42,7 @@ if [ $TRAVIS_REPO_SLUG == "mybatis/mybatis-3" ] && [ "$TRAVIS_PULL_REQUEST" == "
     ./mvnw clean test jacoco:report coveralls:report -q --settings ./travis/settings.xml
     echo -e "Successfully ran coveralls under Travis job ${TRAVIS_JOB_NUMBER}"
 
-    ./mvnw sonar:sonar
+    ./mvnw sonar:sonar -Dsonar.projectKey=mybatis_mybatis-3
 
     # Deploy to site
     # Cannot currently run site this way