Fix travis build, part 4 (refs #376)

Now, a push is a push

.travis/build-sonar.sh

@@ -6,7 +6,7 @@ source .travis/common-functions.sh
 VERSION=$(./mvnw -q -Dexec.executable="echo" -Dexec.args='${project.version}' --non-recursive org.codehaus.mojo:exec-maven-plugin:1.5.0:exec | tail -1)
 echo "Building PMD Sonar ${VERSION} on branch ${TRAVIS_BRANCH}"
 
-if [ ! travis_isPush ]; then
+if ! travis_isPush; then
     echo "Not updating sonar, since this is not a push!"
     exit 0
 fi