made curl request mor readable

contrib/travis-ci.org/trigger-docker-compose-build.sh

@@ -3,6 +3,16 @@
 # trigger build of https://github.com/zammad/zammad-docker-compose on https://travis-ci.org/zammad/zammad-docker-compose and upload it to https://hub.docker.com/r/zammad/zammad-docker-compose/
 #
 
+REPO_USER="zammad"
+REPO="zammad-docker-compose"
+BRANCH="master"
+
 if [ ${TRAVIS_BRANCH} == 'stable' ]; then
-  curl -X POST -H "Content-Type: application/json" -H "Travis-API-Version: 3" -H "Accept: application/json" -H "Authorization: token ${TRAVIS_API_TOKEN}" -d '{"request": {"branch": "master"}}' 'https://api.travis-ci.org/repo/zammad%2Fzammad-docker-compose/requests'
+  curl -X POST \
+    -H "Content-Type: application/json" \
+    -H "Travis-API-Version: 3" \
+    -H "Accept: application/json" \
+    -H "Authorization: token ${TRAVIS_API_TOKEN}" \
+    -d '{"request": {"branch":"'${BRANCH}'"}}' \
+    "https://api.travis-ci.org/repo/${REPO_USER}%2F${REPO}/requests"
 fi