[ci] fix missing local branch issues

.travis/build-deploy.sh

@@ -60,9 +60,12 @@ elif travis_isPullRequest; then
     log_info "This is a pull-request build"
     ./mvnw verify $MVN_BUILD_FLAGS
 	(
-	    set +e
-	    log_info "Running danger"
-	    bundle exec danger --verbose
+            set +e
+            # if ${TRAVIS_BRANCH} is master, the script will fail since there is local master branch
+            git checkout -b ${TRAVIS_BRANCH} origin/${TRAVIS_BRANCH}
+            git checkout -qf FETCH_HEAD
+            log_info "Running danger"
+            bundle exec danger --verbose
 	)
 
 elif travis_isPush; then