Merge pull request #2 from andreasfertig/pushOnlyOnMasterMerge

Push only when merging into master branch.

.travis.yml

@@ -5,7 +5,7 @@ script:
 - make build
 - docker images
 - |
-  if [[ "${TRAVIS_BRANCH}" = "master" ]]; then
+  if [[ "${TRAVIS_BRANCH}" = "master" ]] && [[ "${TRAVIS_PULL_REQUEST}" == "false" ]]; then
     echo "$DOCKER_PASSWORD" | docker login -u "$DOCKER_USERNAME" --password-stdin
     docker tag cppinsights-webfrontend $DOCKER_USERNAME/cppinsights-webfrontend
     docker push $DOCKER_USERNAME/cppinsights-webfrontend