Better branch checking.

.travis.yml

@@ -7,7 +7,9 @@ branches:
   only:
   - master
 after_success:
-  - if [ "$TRAVIS_BRANCH" == "master" ]; then
+  - BRANCH=${TRAVIS_PULL_REQUEST_BRANCH:-$TRAVIS_BRANCH}
+  - echo $BRANCH
+  - if [ "$BRANCH" == "master" ]; then
     docker login -u="$DOCKER_USERNAME" -p="$DOCKER_PASSWORD";
     docker push bcbc/workstand:production;
     fi